Dogpile, put-simply

What is Dogpile?
Dogpile is a metasearch engine, or a search engine that gathers its information from other search engines on the web. It allows users to access many search engines and results simultaneously.

Dogpile is very successful for a multitude of reasons. The three most popular search engines, Yahoo, Google, and Ask Jeeves, have an overlap rate of only three percent. In other words, only three percent of their information is covered in other search engines. Dogpile brings all three search engines together, giving users a more diverse list of search results.

Where does Dogpile gather its information?
Dogpile gathers its information from numerous large search engines. These include About.com, Ask Jeeves, FindWhat, Google, Yahoo, MSN, and Looksmart.
 
What other features does Dogpile have?
Besides being a search engine, Dogpile also has many other great features for users to enjoy. These include Favorite Fetches, Search Spy, a daily joke, weather horoscopes, maps, and the yellow pages. These all contribute to the success of Dogpile.

How does Dogpile earn revenue?
Dogpile earns its revenue through advertisements and sponsored links. Sponsored links and ads appear when search terms are relevant to an advertisers keywords and product. 

For example: When words are searched, the results from the large search engines (Yahoo, Google, and Ask Jeeves) are displayed along side of relevant advertisements.  These ads are placed by advertisers (for a fee) in the hope of having their exact advertisement seen and clicked. 
If the user clicks on a certain ad, Dogpile earns a profit. The amount of the profit varies with the price of the ad space, the value of the key word and the product it is advertising. .