Emily Steel and Jessica E. Vascellaro for the Wall Street Journal reporting on Apple’s iAd program:
>Having originally asked marketers to commit to spend at least $1 million—an amount later dropped to $500,000—Apple is now discussing ad deals with a minimum commitment of just $400,000, according to a person familiar with the matter.
This is the same problem that I see with Twitter’s income model. By saying that you have to cough up $400k you are significantly limiting the pool of potential advertisers.
I am not saying that there should be no minimum commitment, but it seems much to high. My best guess as to why: high quality ads and less clients for Apple to have to interface with.