Dare points to this insightful, if nefarious, post on how Microsoft could crush Google in one easy step.

I've long made the argument that Google is not a technology company, but rather an advertising / media company. Clearly, the distinction between technology and media is at least blurring.  In fact, it was observed at a recent nextNY event that a lot of startups - particularly those in New York - are less about "technology" and more about employing it intelligently.

Though it's unrealistic and unlikely that Microsoft would (or could) ever do this, the post recognizes a simple truth sometimes lost in this discussion: unlike Microsoft (or Apple), Google doesn't really "sell" anything. (Search appliances and Google Premier Apps aren't even on the radar). They are largely dependent on advertising, and most of their products, purchases and partnerships are about securing vehicles for that advertising.

As Henry suggests, Google would be disproportionally affected by the loss of a major vehicle for those ads (or, for example, by the loss of a major advertiser).