Michael Mistretta, the creator of the Deck-like Fusion ad network has written a nice essay on the state of web advertising. He quotes Kyle Baxter:
Online advertising is broken. Web sites place ads to the side of content, and readers learn to ignore it; so web sites put ads in the header, and readers learn to ignore it; so web sites put ads in-line with content, and readers learn to scroll past it; so web sites use video ads and create ones that overflow into the content, so readers stop reading.
I think there’s a lesson to be learnt here for everyone. People don’t like being controlled. The harder you try to enforce things on them, the faster they’ll run away from you.