PPC: If You Aren't Number One...You Still Get Customers

By Jennifer Laycock

With the holiday season just around the corner and small businesses looking for a way to boost their sales, talk often turns to pay-per-click campaigns. Everyone from the small mom and pop shop to giant corporations like Microsoft and Wal-mart make use of paid search advertising to help boost traffic and sales around the holidays. That said, so many advertisers are still living with the false idea that they simply have to bid their site to the number one listing.

An article in USA Today over the weekend talked about the rising cost of pay-per-click ads and the frustration of some business owners about what they "must" spend to maintain their ranking.

In response to the rising ad rates, Jane Moritz recently decided to suspend paid advertising for her small business and work on making her site more Google friendly. "I was paying $1.50 a click, and then it went to $4," says Moritz, who runs a baked-goods site, Challahconnection.com. "Not every click turns into a sale. You're lucky if you get 30%."

Moritz has begun advertising again, but fears that competitors with deeper pockets will bid up prices during the holidays. "I can't afford to pay $6 a click every time someone looks at my site," she says.
This is the type of talk that you read and here quite often when it comes to small businesses and pay per click advertising. When it comes to running short term pay per click campaigns, this problem tends to get even more exacerbated. Many want to be able to run advertising campaigns, but feel that they can't justify the cost because their conversion rates don't result in a profit.

There are several problems with this line of thinking.

1.) You don't have to be number one. - This is probably the hardest thing for most search engine advertisers to understand. The idea of owning that number one spot for their choice keyword has been so beaten into their brains, that many site owners are willing to spend themselves into the red just to stay ahead of their competitors. All the while, savvy competitors are likely sitting quite happily in spots #3, #4 or even #7 turning a nice profit and planning their next vacation. Pay per click advertising isn't all about holding on to the number one spot. It's about matching your bid and position to your conversion rates and your site and finding the happy medium that keeps you in the black. Remember, the number one rule of pay per click is that it is not about buying clicks. It's about buying customers.

2.) They don't have to run ads everywhere. - Many web site owners think that if they are going to run pay per click advertising, they need to run it with every major search engine. Many small business owners are not content to start off with a campaign on Google AdWords or Yahoo! Search Marketing. They also want to run a campaign on Ask Jeeves, Miva, Enhance and a half a dozen other networks. This usually happens because they've found some free coupons to use at each engine. The problem with this is that an inexperienced advertiser can quickly find themselves in trouble trying to manage half a dozen (or even a handful) campaigns. I wrote about this issue just a few weeks back in my article: Starting Small with Pay-Per-Click will Pay Off.

3.) Most small business do not know what they can afford to bid. - The majority of small businesses that decide to run pay per click campaigns for the holidays have no idea how to setup their initial bid rate. They don't know how to calculate conversion rates or determine what they can actually afford. Instead, they set their bid higher than their competitors and hope for the best. Until companies take the time to learn how to set a pay per click budget, they're going to have a hard time turning a profit.

4.) They don't understand that it's the site and not the ad that causes a conversion. - Buying traffic with a pay per click campaign is not difficult. You simply need to find the right word and spend the right amount of money. Buying customers with a pay per click campaign is an entirely different story. Most advertisers still don't understand that what they present to a customer after they click on a link is actually more important than the ad text or keyword that they used to get there. Understanding pay per click landing pages is one of the essentials to being able to turn a profit in a competitive paid search market.

I don't want to make pay per click advertising out to be overly simple. It isn't. It takes time and skill to master the art of fine tuning a paid search advertising campaign so that it turns a nice profit. At the same time, it's also not as scary and difficult as the press, and some advertisers like to make it out to be. Ultimately, site owners need to treat pay per click like they do any other form of advertising. They need to consider the cost, consider the potential reward, and make their decision accordingly.

Designing Effective PPC Campaign Strategies and Tactics

By Ben Wills

As with any successful project, clear definitions of the overall strategy and the tactics necessary to achieve that strategy are essential. Given the nature of pay-per-click search marketing (i.e.: ideally you would put a dollar in, and get two dollars out) and how easily your ad spend can escalate out of control, clear strategies and tactics will become the impetus of your search marketing campaign.

Before I go any further, it would be prudent to digress in order to define the linguistic distinction between strategies and tactics, and how they will be applied throughout this article. I feel that this distinction could, obviously, be used outside of pay-per-click, and I encourage readers to reflect on other ways that this distinction may be applied throughout perceptions in their organization.

As others are often quite more able to articulate concepts better than I, I will be referring to a paper written by Toby Hecht, founder of The Aji Network, called, believe it or not, "Strategies and Tactics: Ultimate and Interim Situations."

Hecht states:

"Tactics are the actions we can take in some specific situation to produce a different specific situation ... Almost all situations we care about require us to perform tactics to produce many interim situations that we do not care about in order to produce the ultimate situation for the sake of which we have acted...

"As we act to produce increasingly valuable ultimate situations, we also invent an interpretation of the tactics we will need in order to produce the sequence of interim situations we have specified. This narrative is called a strategy."

Ultimately, a strategy becomes a series of tactics and the order in which they are executed so as to fulfill an ultimately valuable outcome.

Defining Strategies for Pay-Per-Click

Applying this distinction to pay-per-click, one might define their strategy as over the next three months, increase brand awareness to 100,000 impressions per month at a cost of under $10,000.00, or over the next 6 months, increase ROI above 400% at a minimum ad spend of $10,000.00 per month and increasing to a maximum ad spend of $50,000.00 per month.

Each of these strategies represents the two most common strategies we encounter in the search marketing industry. However, the interesting thing is that we rarely hear people define their strategies as such. Often, they lack boundaries in their assessments of their goals, such as saying "I want to increase my ROI." And that's great, but begs the following questions; by how much do you want to increase it? We can increase your ROI with an ad spend of $50.00 per month, but will that still be valuable to you? How much do you want to earn before defining the campaign a success and how much do you need to spend to reach that goal? What sort of time frame and urgency should this strategy be executed in order to be valuable to your organization?

That said, important considerations in defining your pay-per-click strategy might include the following:

What sort of time frame should you execute your strategy in order for the campaign to be valuable to you and your organization?
What budget requirements and/or restrictions should be imposed in order for the campaign to be valuable to you and your organization?
What is your business objective with this campaign? Branding or ROI? A combination of the two? Perhaps it's to increase conversions, with conversions being anything from the sale of a product to someone signing up on your message board.
All of these are very strong considerations and definitions that must be well thought out before ever considering what sort of tactics you will be implementing towards your strategic goal.

Defining Tactics for Accomplishing Strategic Pay-Per-Click Goals

Applying a distinction of what a tactic is for pay-per-click, understanding the concept of strategies, one then begins to see that every step of the campaign execution then directly relates to the campaign strategy. With a strategy revolving around ROI, web analytics and accurate ROI measurement becomes an essential tactic. With a strategy revolving around branding and impressions, a tactic of bidding on highly searched key phrases might be employed.

Understanding that tactics must both be aligned with your strategy, and that the order in which tactics are executed are just as important as the tactics themselves in achieving your strategic goals, the next step in executing your pay-per-click search marketing campaign is to define those tactics and their order of execution.

Branding Tactics for Pay-Per-Click

The strategy here is exposure to your market. You're not necessarily measuring clicks, you're measuring how many times your message is seen and interpreted by your target-audience. Increasing ad impressions, with consideration for bid position, becomes an important part of your strategy.

For this, we distinguish these key phrases that will generally increase visibility in your market as "research" terms. These key phrases, or key words, are usually searched in greater frequencies, but identify that the searcher is not yet ready to purchase. They are at the beginning stages of the buy-cycle and are collecting information about the product category in which they are interested. Terms that might fall under this category for a music store might be "cd," "music store," or "dance music" etc. Terms such as these display the range of "research" terms that one might bid on in order to increase their brand awareness. Thus, a tactic of bidding on research-centric terms will likely be employed.

Because the strategy is to increase impressions while still sending your brand message, using campaign negative keywords becomes increasingly important. For example, your music store may not want its ad to be displayed when someone searches for "cd duplication" or "cd printing." This being the case, a tactic of effectively researching to implement negative keywords in your campaigns would likely be used.

One final tactic for increasing branding and exposure through pay-per-click search marketing with a restrained budget, and there are many, many others, is write your ad copy in a manner that receives minimal click-through rate (reducing cost), while still remaining competitive enough to continue being "visible" by searchers. In doing so, you effectively maintain price consciousness, maintain visibility, and are able to continue positioning yourself visibly within your market.

ROI Tactics for Pay-Per-Click

With an ROI (Return on Investment) or ROAS (Return on Ad Spend)-based pay-per-click search marketing strategy, click price and your margins become the driving force in your tactical campaign decisions.

Relating to the buy-cycle, executing this strategy employs tactics of bidding on key phrases that fall under what we classify as "Buy" terms. Continuing with the music store example, you might consider bidding on "Yankee Hotel Foxtrot enhanced," an amazing album by the alt-country/folk rock band Wilco. A searcher at this point is well aware of the product they wish to acquire, and they even know that they want the enhanced version of this album.

With a tactic being to find "Buy" phrases, one quickly finds that these kinds of key phrases are searched much less frequently than "Research" key phrases. With an ROI-based strategy keyword research becomes much more acute, and at a depth far greater than a branding-based strategy. Here, you will likely have many more keywords, they will generally cost less per click, they will generally be less competitive, but, ironically enough, they will convert at a much higher rate. We can see, through a new feature that I've seen no previous coverage, on Amazon.com, that the enhanced CD converts at 12%, an amazing conversion rate in any industry that will surely assist in an ROI-based pay-per-click search marketing strategy.

Finally, as with a branding-based strategy, ad copy tactics may be used to greatly impact the execution of your strategy. However, the difference here comes in the manner of writing ad copy to both increase click-through rate, while also encouraging the purchase of your products. While this distinction may appear to be obvious, this tactic is rarely seen executed well, or measured against for improved performance.

Rethinking Your Pay-Per-Click Strategies and Tactics

I hope that this article has proven to be powerful in reshaping the distinctions you make in your current and future pay-per-click search marketing campaigns, and that these distinctions prove to be valuable to your pay-per-click search marketing strategies.

In the next article, we'll be going into great detail of how to effectively measure the tactical progress of your search marketing strategies. After all, if you're not assessing and measuring the proper metrics for your strategy, you'll never know if your tactics are effective.

The Revolution Will Be Televised, Details After These Ads by Google

As it turns out, the revolution will be televised, or sort of televised anyway. Actually, it starts as a commercial.

Google introduced a new age of advertising earlier this week by announcing plans to distribute video commercials on websites in its pay per click AdWords network. The move opens the once exclusive marketing channel of televised ads to a far wider array of small and medium businesses.

Video advertising on websites is not, as such, revolutionary. Online readers of major newspapers such as the New York Times or Wired News are likely familiar with the 30-second IBM dinosaur-head commercials or video ads from the History Channel and Microsoft. The spaces these examples run in often cost as much or more than standard TV ads would. The revolution, as always with the web, revolves around an axis of access and contextual distribution.

The sudden appearance of Google’s online video ad distribution service is going to have multiple repercussions for the $38 Billion US television advertising market. It is also going to present multiple opportunities for search marketers and their clients.

Google users shouldn’t expect to see video ad content on Google branded websites such as Froogle, Google News, or in the general search results, not yet at any rate. The New York Times reported yesterday that the company is, “… considering doing so in the future.”

Starting today, Internet users in the US, Canada and Japan, will see an increasing number of click-to-play video boxes appearing amongst standard text-based AdWords ads on websites displaying Google generated advertising. An example video ad is posted on Google’s Inside AdWords Blog, appearing in a passive-play mode allowing viewers to click on it before it runs. Others have been spotted at, dictionary and translation site, WordReference.com, and on the front page of Blogthings.com.

According to Inside AdWords, “… video ads will compete for placement on sites in the Google content network with other text, Flash and image ads.” Advertisers will bid for placement of their video ads using the same cost-per-click (CPC or PPC) or cost-per-thousand impressions formulas used by competing AdWords advertisers.

The pay per click advertising model is widely credited as the primary factor behind the rapid growth and evolution of the business of search. Google makes over 9/10 of its money from paid search ads showing consistently higher revenues based on the strong growth of its various search advertising services.

A sizable chunk of those revenues have come from the traditional media. The newspaper and magazine sector is trying to diversify online revenue streams, reeling under the weight of eBay, Craigslist, Google and Yahoo. The advent of pay per click video advertising is likely to place broadcast and cable networks in a similar or even less enviable position.

In an Adweek essay published in December 2005, Noreen O’Leary details the multiple challenges faced by traditional advertising distributors when confronting consumers who expect on-demand content delivered immediately. Noting the shift in advertiser spending patterns, she writes, “There was a 25-year lag between when network TV reached mass consumption and when ad dollars caught up. It took 15 years for cable. After 10 years, is the same about to occur for the Internet?”

A lot more money is about to move into the online medium. Even if the next six to twelve months are more a time of trial and testing, there is no way advertisers are going to resist creating their own video ads. The applications for advertisers are endless and suddenly very inexpensive. Search engine marketers, website owners and online advertisers should be preparing to deal with the video advertising market as it expands.

Google appears to be making it as easy as possible for smaller advertisers to upload video ads by allowing for any video format. Video ads are uploaded to Google servers where they are stored and served based on contextually similar content found on the sites displaying them.

"A large percentage of video ads will come from small advertisers," said Gokul Rajaram, a director of product management at Google in an interview with the New York Times. "A small resort owner in Maui probably already has video of their great beachfront property. Now they can put it in an ad and reach a qualified set of users."

Small to medium sized advertisers also have the ability to geographically target ads and to test different versions of their video ads. One of the greatest benefits of online advertising is the ability to track where every click came from and when, giving advertisers and marketing professionals a great deal of instant information about what does and does not work.

In his Screenwerk blog, Greg Stirling notes that the number of targeting options, combined with the ability to track click patters could also benefit larger advertisers testing consumer reaction to commercials before they commit to a much more expensive ad-spend across broadcast or cable television. “One use of this system (and presumably others that will develop shortly) is to "A/B test" creative before launching a campaign on TV. This is sort of like what's being done by some marketers who get users to vote on several different versions of the same campaign online.”

This is potentially the most disruptive move Google has made since the day it opened its doors. Paid search advertising will have a driving force in the migration of advertising money away from the traditional print and broadcast media. That migration, in turn, will cause enormous changes in the search marketing sector.

The timing of Google’s announcement coincides with the purchase of the broadband video advertising firm Lightningcast by AOL last week. Lighningcast inserts commercials into online video content found on sites such as Space.com and Nascar.com.

Unlike Google’s video ads, Lighningcast executive Matt Wasserlauf is quoted by the NYTimes saying, larger marketers would rather their commercials be included in streaming content instead of being an include on a static web page. "No one will click to watch a Pampers ad," he said. For example, he said, Procter & Gamble would rather "put Pampers on relevant or entertaining content."

What consumers prefer remains to be seen but, if Google has placed its bets well, allowing consumers and advertisers more control over choices made in the process of exercising their preferences can only be a good, and incredibly profitable, thing.


Discuss this article in the Small Business Ideas forum.

http://www.searchengineguide.com/jim-hedger/the-revolution.php

Managing a Responsible Pay-Per-Click Campaign

OVERVIEW
What is PPC?
Pay-Per-Click is a paid form of advertising, popularized mostly by the "search engine" Overture (formerly GoTo). The concept is fairly simple. Businesses bid to be placed at or near the top of the search results for particular keyword phrases. The bidding is done on a "per-click" basis, meaning that a company pays a specific amount every time the engine sends them a visitor. In addition, the top results on Overture also show up in the results of many of the popular search engines (usually listed as "sponsored" or "featured" results). Google has a similar version of PPC (AdWords Select) that has taken over some of the engines that used to display Overture results (most notably AOL Search).

Advantages
Pay-Per-Click campaigns have some advantages over traditional search engine optimization. First of all, they require no changes to a current site's content or look to obtain top positions, just a willingness to pay. Also, the implementation of a pay-per-click campaign is relatively quick- it can take just a few minutes to start getting targeted traffic, versus sometimes months for standard SEO campaigns. Finally, unlike search engine optimization, the implementation of a PPC campaign is relatively easy and does not necessarily require any specialized knowledge (although experience with search engine marketing and keyword research is a definite advantage).

Limitations
Of course, there are limitations to this type of advertising. New bids can lower the positions of other firms, and many will react by raising their bid to regain a previous ranking. Monitoring of positions becomes crucial. These campaigns can also become prohibitively expensive, depending on the competitiveness of the keyword phrases and the aggressiveness of the competition. In addition, many of the "savvier" search engine users have learned to recognize PPC results as paid advertising and bypass them without consideration.

THE PROCESS

Determining Visitor Worth
Determining how much each website visitor is worth is vital to the success of a pay-per-click campaign. If it costs $50 in click-throughs to make a $40 sale, the campaign has failed. The formula is relatively simple, but some specific historical data is necessary. In the most rudimentary form, it is the profit from the website over a given period divided by the number of total visitors for the same period. If a site netted $1000 in profits from goods or services in a given period, and there were 2,000 visitors during the same period, each would theoretically be worth 50 cents (profit divided by visitors). But this is only the breakeven point. Depending on the desired profit margin, the optimal price to pay per click would probably be something much less than 50 cents. Popular keyword phrases can often run more than this, so it then makes sense to bid less money on less popular terms to pay an acceptable amount per visitor.

Selecting Keyphrases
As with typical search engine optimization, keyword research is critical to the success of a PPC campaign. Unlike typical search engine optimization, there aren't practical limits on the number of phrases to target. Usually, there is no extra cost to add as many keyword phrases as possible. This makes the keyword selection process easier, since there is not a good deal of resources committed to optimizing a site for a particular keyword set. Under-performing keywords, while still an annoyance, do not cost extra (except for the time involved in setting up the account). To help identify keyword phrases, Overture has a tool on their site that allows advertisers to see how often particular search terms are actually typed in their engine. It also gives out popular suggestions based upon the terms you enter.

Writing descriptions
With a typical search engine description, the object is to entice as much traffic into a site as possible in the hopes of converting that traffic into customers. With PPC, a different approach is mandated. It is undesirable to pay for unlikely prospects, so the description is designed to eliminate the "tire kickers" while attracting highly targeted traffic. For this reason, the description should describe exactly what the business offers- a company wouldn't want to pay for every visitor looking for "insurance" if they only sold renter?s insurance, for example. At the same time, proven marketing copy techniques should be employed to insure that the description is enticing enough to attract ideal prospects.

Monitoring and Analyzing
It is crucial to the success of any PPC campaign that it be monitored regularly, since positions can and do change every day. Since the top three Overture or Google AdWords results are what typically show up on most partner engines (some display more), the competition for these spots can be fierce, and bidding wars are common. If the price gets too high, it is usually prudent to withdraw and pursue a different keyphrase (the only way to really "lose" a bidding war is to pay too much for each visitor!). Apart from position monitoring, it is important to track and analyze the effectiveness of individual keyword phrases on a monthly basis. Viewing click-through rates and studying visitor habits can lend valuable insight into their motivations and habits, and help to further refine a Pay-Per-Click campaign.

CONCLUSION

Pay Per Click campaigns can bring large numbers of highly targeted visitors to your website. However, these campaigns can become prohibitively expensive (and unlike "traditional" search engine optimization, the costs of any PPC campaign are likely to increase in the near future due to the increased popularity of this form of advertising). It is crucial to the success of the campaign that you pay a reasonable price for each visitor, that each visitor is highly targeted, and that you monitor your positions to maintain your exposure over time.


http://www.searchengineguide.com/scott-buresh/managing-a-responsible-payperclick-campaign.php

Pay Per Click Affiliate Programs

Some pay per click search engines run affiliate programs that allow you to place their search form on your site. You are then paid for the visitors from your site that use the search form and click on one of the results.

Important Considerations

A very important point to keep in mind with pay per click is you must test, test, and test some more. Don't start off with a major investment. Start with the minimum and see how the search engine performs in terms of the traffic it delivers and how well that traffic converts into paying customers.

An essential part of your testing is having a method in place that allows you to track your return on money invested.

For example, if your goal is to bring in new subscribers to your newsletter, you could direct visitors arriving from your pay per click link to a subscription form set up just for them. You can then monitor how many clicks actually result in a new subscription. As such, you will know how much you are paying for each new subscriber.

Before spending any money with a pay per click search engine, be sure they can answer the following questions:

- How many searches a month are performed at the search engine?

- What major search partners or affiliates does the search engine have?

- How many searches are generated each month by the search partners or affiliates?

-Is it possible to opt out of having your listing appear in the results of the affiliate sites?

-What fraud prevention mechanisms are in place?

-What is the procedure for filing a "fraudulent clicks" report?

-Will an account be credited for fraudulent clicks discovered?

-Is it possible to opt out of having a listing appear for searches originating from specific countries?

Is there a posted terms of service for search partners or affiliates. Look for search engines that have very strict guidelines for dealing with their search affiliates. This is important because you want to be sure the search engine is working hard to prevent fraud among its affiliates.


To learn more about Pay Per Click advertising:

http://www.searchengineguide.com/payperclick.html

Which Search Engines Allow Pay Per Click Advertising?

There are hundreds of pay per click search engines.
Generally, the larger the pay per click search engine, the more you will have to bid to get to the top for your keywords. This is why it is worth investigating different search engines to find what it would cost to bid on your keywords and how much traffic they draw.

The largest companies in the pay per click industry are Yahoo! and Google. Google is not a pay per click search engine, but it does provide pay per click advertising in text ad boxes to the right of search results it delivers. It also delivers pay per click ads to other content sites.
To find more pay per click search engines, take a look at those listed in the box in the right column of this page.

These pay per click search engines are not as large as Overture and Google, but they are worth a look. As mentioned above, one advantage these search engines can provide is they generally have lower costs per click to rank for a keyword than the larger search engines.
In addition to the general pay per click search engines, you may also be able to find thematic search engines that serve your industry or specifically cater to your target audience.

What Is Pay Per Click?

Pay per click advertising on search engines allows you choose keywords you would like your site to appear for when a search is performed. You decide how much you are willing to pay each time a person clicks on the search results. The more you are willing to pay per click, the higher your site will appear in the results for the keywords you choose.

http://www.searchengineguide.com/payperclick.html

References

^ Website Traffic Yahoo! Search Marketing (formerly Overture) Yahoo Inc., Accessed June 12 2007
^ Shopping.com Merchant Enrollment Shopping.com, Accessed June 12 2007
^ Sell on Google Google Inc. Accessed June 12 2007
^ Overture and Google: Internet Pay Per Click (PPC) Advertising Auctions, London Business School, Accessed June 12 2007
Retrieved from "http://en.wikipedia.org/wiki/Pay_per_click"

wikipedia.org

External links

Adwords Blog
Yahoo Blog
Adcenter Blog

See also

Internet marketing
Online advertising
Interactive advertising
Compensation methods
CTR - Click-through rate
CPM - Cost Per Mille
eCPM - Effective Cost Per Mille
CPT - Cost per thousand
CPI - Cost Per Impression
PPC - Pay per click
CPA - Cost Per Action
CPC - Cost Per Click
eCPA - effective Cost Per Action
Ad serving
Search engine marketing
Search engine optimization
Niche blogging

History

In February 1998, Jeffrey Brewer of Goto.com, a 25 employee startup company (later Overture, now part of Yahoo!), presented a PPC search engine proof-of-concept to the TED8 conference in California.[4] This and the events that followed created the PPC advertising system. Credit for the concept of the PPC model is generally given to the Idealab and Goto.com founder, Bill Gross.
Google started search engine advertising in December 1999. It was not until October 2000 before the adwords system was introduced. Allowing advertisers to create text ads for placement on the search engine. However PPC was only introduced in 2002, until then, advertisments were charged at CPM. Yahoo Advertisments have always been PPC, since its introduction in 1998.

Pay per call

Similar to pay per click, pay per call is a business model for ad listings in search engines and directories that allows publishers to charge local advertisers on a per-call basis for each lead (call) they generate. The term "pay per call" is sometimes confused with "click to call"Click-to-call, along with call tracking, is a technology that enables the “pay-per-call” business model.
Pay-per-call is not just restricted to local advertisers. Many of the pay-per-call search engines allows advertisers with a national presence to create ads with local telephone numbers.
According to the Kelsey Group, the pay-per-phone-call market is expected to reach US$3.7 billion by 2010

Online Comparison Shopping Engines

"Product" engines let advertisers provide "feeds" of their product databases and when users search for a product, the links to the different advertisers for that particular product appear, giving more prominence to advertisers who pay more, but letting the user sort by price to see the lowest priced product and then click on it to buy. These engines are also called Product comparison engines or Price comparison engines.
Some Online Comparison Shopping engines such as Shopping.com use a PPC model and have a defined rate card. [2] whereas others such as Google Product Search, part of Google Base (previously known as Froogle) do not charge any type of fee for the listing but still require an active product feed to function.[3]
Noteworthy PPC Product search engines include: Shopzilla, NexTag, and Shopping.com.

Keyword PPCs

Advertisers using these bid on "keywords", which can be words or phrases, and can include product model numbers. When a user searches for a particular word or phrase, the list of advertiser links appears in order of the amount bid. Keywords, also referred to as search terms, are the very heart of pay per click advertising. The terms are guarded as highly valued trade secrets by the advertisers, and many firms offer software or services to help advertisers develop keyword strategies. Content Match, will distribute the keyword ad to the search engine's partner sites and/or publishers that have distribution agreements with the search engine company.
As of 2007, notable PPC Keyword search engines include: Google AdWords, Yahoo! Search Marketing, Microsoft adCenter, Ask, LookSmart, Miva, Kanoodle, Yandex and Baidu.

Categories [from wiki]

PPC engines can be categorized into two major categories "Keyword" or sponsored match and "Content Match". Sponsored match display your listing on the search engine itself whereas content match features ads on publisher sites and in newsletters and emails.

There are other types of PPC engines that deal with Products and/or services. Search engine companies may fall into more than one category. More models are continually evolving. Pay per click programs do not generate any revenue solely from traffic for sites that display the ads. Revenue is generated only when a user clicks on the ad itself.

http://en.wikipedia.org/wiki/Pay_per_click

About Pay per click From Wiki

Pay per click (PPC) is an advertising model used on search engines, advertising networks, and content websites/blogs, where advertisers only pay when a user actually clicks on an ad to visit the advertiser's website. Advertisers bid on keywords they believe their target market would type in the search bar when they are looking for a product or service. When a user types a keyword query matching the advertiser's keyword list, or views a page with relevant content, the advertiser's ad may be shown. These ads are called a "Sponsored link" or "sponsored ads" and appear next to, and sometimes, above the natural or organic results on search engine results pages, or anywhere a webmaster/blogger chooses on a content page.

Pay per click ads may also appear on content network websites. In this case, ad networks such as Google Adsense and Yahoo! Publisher Network attempt to provide ads that are relevant to the content of the page where they appear, and no search function is involved.

While many companies exist in this space, Google AdWords, Yahoo! Search Marketing, and MSN adCenter are the largest network operators as of 2007. Depending on the search engine, minimum prices per click start at US$0.01 (up to US$0.50). Very popular search terms can cost much more on popular engines. Arguably this advertising model may be open to abuse through click fraud, although Google and other search engines have implemented automated systems to guard against this.