If they can build a huge audience, I'm sure some artists will pay... will certainly be interesting to see how it all plays out (and if any major bands get discovered through Earbits)!
I guess I'm wondering, where's the filter? What will make the music that I hear at this site better, on average, than the music at any other site?
Because it sure as hell isn't the fact that artists will be able to pay for exposure. IMO there's just no way around it, pay-for-play is a listener-hostile dynamic, there's absolutely no way it could improve the quality of what I listen to.
Actually, maybe that's a lie, there's one tiny way it can help: if pay-for-play is limited only to the acts that have not had enough exposure for the "market" to figure out whether they're any good, then it can improve what I hear by letting the artists pay to make sure that they've actually been listened to by enough people to be fairly judged. The real problem with payola schemes is when artists that have already had plenty of exposure can use money to make sure that they have more exposure than even the organically successful acts - this is something that Earbits needs to make sure it avoids, and if it is successful, this will mean some tough decisions, because they'll have to start turning down money that their biggest customers want to give them ("What's that, Mr. Combs? You want to buy up 90% of our play time for the next two months and fill it with your label's shitty music, and you'll pay us six times what we made last year? No thanks, that would be unfair.").
In any case, I think more needs to be done to figure out a compelling pitch to users. The payola side of it is not the right thing to emphasize - it's going to offend musicians, and it's not going to attract users.