While Yahoo SM and Google AdWords are the only pay per click site to have achieved top 10 search engine status, other pay per click engines are vying for recognition. Here is a list and a brief description of some of the more notable ones.

Google Adwords - AdWords are text-based ads that are displayed next to Google and AOL search results. The ads are also displayed next to selected content sites. These text-based ads function on a pay-per-click basis and are referred to as AdWords. Google rewards well-targeted, relevant ads therefore the top position is not always held by the top bidder. For example, the top bidder normally has the top position, however, if certain ads are clicked on more often than others, those ads will get a boost in their position.

Yahoo SM (Search Marketing) (formerly Overture) - The most popular search engine of its kind, Overture is a pioneer in its field. Formerly known as Goto, Overture burst onto the scene in 1999 defying critics who believed the venture would fizzle with consumers, due to irrelevant search results. Today, Yahoo SM allows webmasters to choose their own descriptions and titles, helping to drive highly targeted traffic to their web sites. Yahoo SM also feeds its top 3 results to Altavista, MSN, Yahoo and other search engines. So if your web site is in one of the top three spots at Yahoo SM, it also appears in the listings of those other search engines, dramatically increasing your traffic. But while your web site will certainly get more exposure on Yahoo SM, and consequently more visitors, keyword bids tend to be more expensive. Overture became Yahoo Search Marketing in 2005.

FindWhat - An heir to the pay per click throne, FindWhat has experienced rapid growth. FindWhat's top 10 results are included in metasearch results for Metacrawler and Dogpile. It offers web masters a lot of flexibility. They can modify titles and descriptions, as well as add and remove keywords and change bids. Webmasters can also request reports on transactions and keyword cost, and receive listing and activity overviews. While FindWhat generally has much lower bids than Yahoo SM, it also has less traffic.

eSpotting - A U.K. based search engine which receives good traffic from its partners. Its top 5 results also appear in Yahoo.co.uk. Accounts start at £50. The only real competition to Yahoo SM and Google AdWords, but it only really competes in the UK.

Kanoodle - With 410 million queries each month, this pay per click search engine receives a fair amount of quality traffic -- at least for highly-searched keywords. Kanoodle's top listings also appear in Search.com, Webcrawler and Dogpile.

ePilot - ePilot receives over 200 million monthly searches across its search distribution network. Its results are displayed on partners' sites such as Yellowpages nationwide.

goClick - Features an extremely user friendly and effective account management system. goClick's BidMaster AutoBid tool allows you to set your maximum bid and have it adjusted daily to $0.01 higher than the next highest bid.

7Search - This pay per click search engine provides immediate e-mail notification when you are outbid for the top ranking on a keyword, and includes a keyword generator tool.