Fair enough. My own empirical observation is that some ad targeting initiatives (the aforementioned Facebook example, the Amazon example) DO result in the delivery of relevant ads, which are actually beneficial to both the buyer and the seller. I won't argue that it guarantees that all ads will be relevant. But if I'm going to see a stream of X ads in a given day, I would personally prefer that the percentage of them that are for things I'd legitimately be interested in, be as high as possible.