I've turned down countless requests from companies to advertise on my own costume design site, which got a lot of traffic when only a few such sites existed. Some of the companies were related to costuming, but some were only barely related, or not at all (furniture imports, for instance).
I've noticed sites that DO accept ads get ugly real fast, with clashing styles and color schemes clamoring for attention, some even animated. As a designer, I am repelled by the visual discord, if I can't manage to ignore it.
On the other hand, I know the ads are a valuable source of revenue that supports sites I like and allows them to continue.
I think spam fatigue got to most of us a long time ago. I have a great aversion to becoming a quasi-spammer myself, that's why I resist the ubiquitous urging to use networking sites to promote relentlessly. It's bordering on a mental block, in my case.
I don't have any answers.

