When Yahoo signed up CNN.com as an online-advertising customer in 2004, bumping out Google, it was seen as a victory that gave Yahoo's then-nascent search business a significant boost. Now, however, Google has reversed that loss, displacing Yahoo as both CNN's search tool and its keyword ads provider. CNN, one should note, is a division of Time Warner, a former investor in Google and a co-owner with Google of AOL. For Yahoo's search business, it's a staggering loss; for Google, a predictable victory.

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