I think user collections are an underutilized feature. They could potentially be a way to discover music, but they are somewhat hidden at the moment.

The collections tab on the side of a page is at the very bottom and gives you a link to the relevant collections, which means that most people will never see any of them. One way to fix this would be to list a handful of the public collections (say, five) in the collection tab. For example, Bob Dylan's page would show arist.on's blues collection. The best way to calculate this would be to select the collections with the most subscribers first in order to encourage the creation of collections built around discovering new music (e.g. "Rainy Night Albums") rather than collections that are meant for showing off a music collection alone.