I can vouche that I've found way, way more bands through itunes than I ever did before.
when browsing, I can hear clips of new bands and make a much lower risk single song purchase to try them out.
back in the cd and casette days, I'd have to base purchases on the cover, and usually I would just stick to bands I knew rather than throw down $12-15 on a chance purchase.
now, since ebooks tend to have a few chapters available to sample, I can do the same with books still.