Well, like I said, they're already doing ads in between songs in typical radio fashion. The pop-ups seem to be synchronized with those ads. I say keep the radio ads but jettison the popups. I have learned to tolerate radio ads, but popups are unacceptable. They disturb me while I'm trying to do other things, and then I have to go close them, etc.

Yeah, the popups are annoying enough that they'd encourage some people to pay for the premium service, but they're also annoying enough to make me say "screw it" when testing the thing out.