I was just listening to Pandora and heard my first Audio AD. I think this might be a necessary evil as they have had trouble getting fair rates from the music industry. I believe thier current rate is near 3x the rate paid by terrestial radio. Below is a snapshot of how it looks – Please understand and direct your thoughts and feelins at the music industry not pandora. They are doing great things!
Pandora Starts invasive (but necessary) advertising