For some reason Microsoft's search demographic has always converted better for me, and Google has always seemed to be more about research and window shopping.
Google somehow keeps more buyers for themselves / 'makes' them click on ads? Bing is losing money (part catch-up infrastructure probably but still) and Google announces record earnings each time even as they lose market share.
eHow had /has a business model: read a bit of so-so content and get the real answer by clicking on ads. Would most people visiting G know or care that they were ads? In many monitors the ad/content bg colors are identical and 'ads' is written in tiny letters, way to the right and in almost hidden text color. Google even brags about their data mining capability so who knows what the LSI and personalization are truly about? Now they eve change your title, description and meaning of the page (and ironically might even penalize your entire site if visitors from G are not 'engaged')'
If it walks like a duck...we need to see if it may really be a duck. Not sure how an average user will react if 'jeans' brings, say, Nordstrom, Macys...Gap in top. Or the major insurance cos for 'insurance.' Maybe they'll click on an ad for a less expensive store or a insurance comparison site? All these can be tracked, quantified and of course adjusted to your history, income, region, site visit history etc etc.... So, for example, if I'm rich and G knows it, and Target shows #1 for 'jeans', I might click on a Nordstrom ad.