If you divide total Pandora royalties by the number of artists in the catalog, you'll realize that these "unknown" artists they're showcasing are outliers by a huge margin, and probably put into rotation just for a publicity purpose like this.
edit: spelling
That's why I don't listen to Pandora. They keep trying to replay the same old music again and again.
Frankly, I don't see anything innovative about Pandora. They just use a crude classification of songs. I already have enough of radio stations, thank you very much.
Edit: Oh, I see. I assume these artists just have much better music than they have marketing. It would be interesting to know what sets them apart, though.
I'm also wondering if those unknown artists arent possibly algorithm glitches or they just luckily match some sonic parameter so they keep coming up in the playlist. I'm so cynical :)
http://tech.fortune.cnn.com/2011/06/13/pandora-the-money-los...
I wonder how much Pandora makes (or loses) on that artist.