Most of my personal friends and family know that I'm really turned off by most forms of advertising (specifically excluding word of mouth recommendations which are not spamming). My main problem with it, is that it hits most people where they're most vulnerable -- their subconscious. We would assume that advertising doesn't directly influence our buying decisions, however that assumption is almost always flawed. Since I've started watching more TV, I've caught myself thinking that I needed a new Dyson, Kenmore super dishwasher, and other shiny things before realizing that I'd been duped.
Today, I was particularly caught off guard while Googling for a JPA question. I was looking at the discussion thread, and at the end there was a small non-intrusive advertisement:
However, the way this ad is integrated into the rest of the site (click for context) leads to a high probability that it is clicked by fast skimming answer-seekers like myself. Grr... I was fooled by a banner ad, what year is this?
This seems like it wouldn't be too big of a problem for active members of the site in question, but their content is google fodder, and the seekers are not going to keep coming back to coderanch. For similar reasons I avoid all links to w3schools or bigresource. If you're advertising legitimate goods and services, you don't have to resort to tricks for clicks.