I am lazy and don't bother to try to avoid ads. These days, the ads are virtually all from online bicycle stores, etc. But usually, they are trying to sell me things I've already bought - Competitive Cyclist keeps trying to sell me Ultegra cassettes based on a search (and purchase) of a cassette in November or so.

So they are well-targeted, but some times a little behind the curve.

I've been dreaming of getting a folding bike, and I've done a few searches, but thus far Bike Friday and Dahon have yet to target me. They will soon, I guess.