In a long-awaited pairing aimed at taking on Google, Yahoo will handle ad sales while Microsoft gets the real prize: data on who’s doing what online

Ever since Microsoft (MSFT) made its $45 billion bid for Yahoo (YHOO) in early 2008, it was clear the software giant was serious about taking on arch-rival Google (GOOG) in the lucrative Internet search business. And now, after years of talks with Yahoo, it seems Microsoft has achieved its goal. In a 10-year deal announced in the early hours of July 29, Microsoft became the clear No. 2 in a market long dominated by arch-rival Google.

In a deal that presages its departure from a market it helped pioneer, Yahoo will scrap its own efforts to best Google in search and instead rely on Microsoft’s recently debuted Bing search engine. Ads placed next to those search results would be served up not by Yahoo’s ad platform, dubbed Panama, but by a Microsoft technology called AdCenter. Yahoo CEO Carol Bartz “is essentially giving up on search,” says Danny Sullivan, editor of Search Engine Land.

Yahoo salespeople will continue to sell search ads that appear on both Yahoo sites and on Bing, and Microsoft agreed to let Yahoo keep 88% of the revenue on ads that appear on Yahoo sites. But Microsoft will nevertheless reap a reward that’s more valuable in the long run. The data on computer users’ online search and buying habits would ultimately reside on Microsoft’s computers, thereby improving its ability to automatically serve up the most relevant ads. “If Microsoft is running the underlying ad technology, it doesn’t matter who is selling the ads,” Sullivan says. “In the end, Microsoft will hold all the cards.”

He adds that most advertisers place ads by filling out online forms, with no involvement from salespeople. Maintaining control of sales makes the deal “sound rosier for Yahoo than it really is, because in the end Yahoo won’t have the technology needed to compete.”

INSURANCE FOR MICROSOFT AND BING

Microsoft wins in other ways. The deal gives a big boost to Bing. The combined search market share of Yahoo and Microsoft would approach 30%. That’s still far below Google’s 65%, but analysts say it may provide enough of a critical mass at least to stave off further Google advances and help the enlarged search engine gain some ground. At a minimum, the deal doubles as a kind of insurance policy for Microsoft, in case all of the positive buzz about the Bing search engine doesn’t translate into actual market share. By adding Yahoo’s 20% market share, Bing assures its place as the only search engine provider other than Google with size that really matters.

Popularity: 4% [?]