Yeah, I think that there are quite a few music schools that do it for ease of materials access and additional revenue. There is something quite useful for that... but most of the musicians that do it are usually viewed in a pretty shady light! Sometimes, I think some of the music stores are pretty damn dodgy as well... the one that I'm thinking about has an old guy who runs the classical section for decades... and he has no idea what he is talking about, but he manages to impress the parents who don't know anything.