• by Gavin O'Malley  @mp_gavin, August 10, 2005

Yahoo!'s claim this week that its search index now includes over 20 billion Web documents and images has drawn mixed reactions from experts and rivals alike. Until the announcement, it was assumed by many that Google had by far the largest search breadth.

A Google spokesman said the company is currently investigating Yahoo!'s claims.

Prior to Yahoo!'s announcement this week, its index was estimated to be in the 6 billion to 8 billion range, but the company was unwilling to disclose its actual size. Yahoo! is now saying that its index covers 20.8 billion online objects, made up of about 19.2 billion documents and 1.6 billion images--partly because of a recent upgrade. Google, for its part, claims to track 11.3 billion objects--which consist of the some 8.2 billion Web pages and 2.1 billion images, as well as material from its group discussions.

Some analysts, like Unicast's Director of Marketing David Berkowitz, brushed off Yahoo!'s newly reported number as an unknowable and even arbitrary estimate that means little to marketers.

"People who've been in the business for any length of time already know exactly who they're competing against and what keywords are relevant," said Berkowitz, "so an extra five billion arbitrary results isn't going to change anything."

Berkowitz, however, did suggest that the perceived besting of Google--which claims to index just over 10 billion "objects"--could give Yahoo! an edge in the minds of consumers. "From the surveys I've seen, people tend to associate Google with comprehensiveness, and no one so far has been able to trump them on that aspect of their brand," Berkowitz said. "But if I, as a consumer, hear that Yahoo! is now the most comprehensive, I might rethink my perception of both search engines."

Mike McGuire, a Gartner research director, said the larger index could indeed weigh in Yahoo!'s favor with both consumers and marketers, but that it was too early to know.

"Anyone dismissing these numbers right away is just guessing," McGuire said. "We'll have to wait and see whether this actually equates to a more comprehensive search, but for now I think a lot depends on how Yahoo! sells this message to advertisers and the public."