I suppose when I intentionally go to a site, then I shouldn't be surprised to get ads for whatever I looked up. Though it is still surprising where they come out. But if one doesn't (intentionally) go to a site, then it seems strange, or even wrong. I often enough look up something without actually intending to buy it, such as if I want to mention it in discussion here. But obviously it doesn't know that. My favorite, though, when I was looking for articles about radial transmission lines (that is, the electrical version) and getting ads for transmission (as in cars) repair stores.