I just defriended someone who works for a social game company because they were pushing waaaay too many ads through to my feed. I felt bad about doing it because I don't mind the guy on a personal level, but shit it was annoying. Anyway, having defriended him I reloaded my news feed only to find that the ad was still there!

Now, maybe that's a one-off and the servers hadn't quite synchronized yet, but damn. Facebook makes me dump my friends to avoid ads and still gives me the ads!