The major labels have marketing strategies for breaking in new acts, that involve some form of making people think that they themselves have *discovered* someone new and cool–that they then can tell others about. The marketers know that they have to get a critical mass of people to feel that, so that the *discovery* spreads to a mass market, and doesn’t just remain the “secret” of a select few dedicated fans.
The marketers play a manipulative role (and, from my second-hand experience, I know that they can be really devious), but we, the people, tend to embrace that manipulation because, I think, it helps us maintain our social status. We need to affirm that we aren’t alone in the music we like, and that we like “cool” music, etc.
This is part of why / how music-oriented, peer social networks can break new acts–and, also can be manipulated. . .
Also interesting about the cover songs: the more traditional practices of establishing a music career involve proving that you can cover the standards / classics before introducing your own, new material. . .