I keep banging on about creative co-ops on the Internet and yet I forget to mention one of the oldest and most successful? Doh!
Book View Cafe is a 100% author-owned publishing co-op selling ebooks. 90% of the cover price goes directly to the author and 10% maintains the co-op. Best part? No DRM! https://bookviewcafe.com/bookstore/
I should also point out that one of the founders of Book View Cafe was the late Vonda McIntyre, who we all miss terribly.