Well, in the end that goes for advertisers and website makers both, I guess.
I think it is a pretty difficult conundrum, with stalking and annoying ads being unethical, but easy advertising services being a good thing for website producers.
I'm working on my first commercial site, but don't know how to go about funding it in a way that wouldn't bother me - not everyone is willing to pay for membership and I'd like to be able to use ads without being an douchebag.
I just don't know how yet.