Yes, Bandcamp is a pretty good example of a fairly pure long tail aggregator. They're a private company but they seem to be modestly profitable. Which I guess can be glass half full or half empty depending on your perspective. i.e. you can make money for yourself and for at least some long tail artists, but it's not blockbuster returns.
I think I’m really done with the idea of success being a unicorn company. Bandcamp profitably supports something like 100 employees and makes thousands of indie musicians a significant amount of money. That feels like a smashing success to me. I don’t need a private island.