I did a search (not on Google) for an unusual sensor the other day. I found a candidate and went to their web site and looked at some data sheets. All of a sudden, I see ads for this company on every page with Google ads (and ther are a LOT of those!)

I feel sorry for the company - obviously, Google hasn't been able to place those ads because its such a niche product and need. So once they "got a live one", they started serving me this company's ads *everywhere* (and I research and browse a *lot*).

I'm pretty sure I was perhaps the only target of their entire ad budget for the month - I was literally served ads for this tiny company *thousands* of times.

Note that only Google gained here - the ads didn't make me any more likely to buy a product I already knew about (and won't need for months in any case), and they did nothing to actually help the company reach more potential buyers. But the ad inventory was placed, and no doubt, each superfluous impression dutifully billed for...