It's quite simple actually. People have become immune to banner advertising. In an effort to actually get people to look at advertisements, advertisers have gone completely gonzo with their ads in an attempt to catch your eye. If you are curious enough to investigate why there is a guy laying with a horse making $47 an hour, perhaps you'll give them some money for whatever product it may be that they are selling.

So in short, they got your attention. You passed that attention on to others. They did their job very well.