Bandcamp only makes money when you make money. We considered building the business around advertising, but…well, OK, we never really considered that. We did consider building it around subscriptions, but under that model, given the option of either developing a feature to increase your sales by 20%, or dinking around with service tiers to try to boost our subscriptions by 20%, we’d have to choose the latter. By building the business on a revenue share, our interests are perfectly aligned with yours: we only succeed when you succeed.
This is the post announcing Bandcamp's business model (15% of sales). Bandcamp is the go to solution for putting a band's music / discography online, and their statement above just makes so much sense: their needs / means of success as a business are 100% aligned with their customers.