A look at how the Microsoft-Yahoo deal will work

Although Yahoo and Microsoft could soon be working together on Internet search, their collaboration would mostly occur behind the scenes.

Consumers would still see Yahoo's logo striped across Yahoo.com. The only nod to Microsoft would appear when a user gets results from a Web search. At the bottom of the page Bing, Microsoft's search engine, will get credit for providing the results.

While it handles search requests at Yahoo, Bing would still be fielding queries at MSN.com, Bing.com, and other Web sites owned by Microsoft. And nothing figures to change in the way Microsoft accepts search requests from cell phones and "toolbars" added to Web browsers.

The Yahoo-Microsoft deal is noteworthy because it aligns two of the Internet's most powerful players in an attempt to take search kingpin Google down a notch or two. But it's common for one Web site to rely on another company to run its search engine and/or the ads the show up alongside search results.

Google even sells search ads on a rival search engine, Ask.com. AOL has been depending on Google for both its search results and search advertising for years. When their contract expires in December 2010, Microsoft is expected to bid aggressively against Google to provide the search engine on AOL.

Why all the competition? Because advertisers bid for the right to show their ads alongside certain search terms. The marketers pay the search engines when a user clicks on an ad. That means Microsoft and Google are trying to make the audiences for their search engines as vast as possible. The more eyeballs they have, the more advertisers are likely to pay.