SAN FRANCISCO (CBS/AP) — Microsoft is trying to skewer Google as a lousy holiday shopping guide in its latest attempt to divert more traffic to its Bing search engine.

The attack starts Wednesday with a marketing campaign focused on a recent change in how Google runs the part of its search engine devoted to shopping results. The revisions require merchants to pay Google to have their products listed in the shopping section.

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In its new ads, Microsoft Corp. contends the new approach betrays Google Inc.’s longstanding commitment to provide the most trustworthy results on the Web, even if it means foregoing revenue.

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Google defends the fee-based approach as a way to encourage merchants to provide more comprehensive and accurate information about what they’re selling.

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