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Most clicks on Yahoo search ads do not occur on Yahoo's search results. They happen on one of Yahoo's 1,196 advertising partners. The problem is, as the above chart from SEOBook indicates, these ad clicks on syndicated search results pages don't lead to sales conversions for advertisers as often as clicks on Yahoo's own pages do. Unlike Google, Yahoo doesn't let advertisers opt out of having their ads served on third-party sites. As a result, Yahoo ads for the same keywords are worth less to advertisers — two-thirds less, in some cases. Buying the keyword "mortgage" on Google costs $15.58 per click compared to $4.85 on Yahoo.