Not well targeted ads! One of the forums I frequent has a fairly new ad up almost all the time. A number of people have commented on their experiences purchasing the products from that vendor and as a result, many more (myself included!) plan to buy from them when the need arises. It's a simple banner ad and clicking it takes you to a gorgeous website that is a perfect showcase for what they're selling.

I really don't think most people (non-developers) dislike ads; we dislike annoying, generic ads that have nothing we're interested in.

Then again, my wife and I love the "messing with sasquatch" TV ads because they're so funny although I can't even remember what they're selling!