Interesting rumbles in the world of indie publishing (we used to call it self-publishing, but that's out these days). Seems there are click farms gaming the Kindle Select program and a number of authors are advocating direct to consumer sales. I've not been in that mode, but reading a few recent articles, it makes sense and seems to be technologically feasible now to deliver the format the reader wants.
Here's the article on Kindle click farming: http://www.thepassivevoice.com/2016/04/ku-scammers-on-amazon-whats-going-on/
Using Shopify to deliver your work: https://www.facebook.com/groups/441469159372773/permalink/515889508597404/
And evidently this program lets you deliver books straight to the Kindle, etc. Selz https://selz.com/blog/7-benefits-of-using-a-facebook-store-to-sell-direct/
I don't think these have any affiliate links in them -- just picked them up as I went to read the articles. And the Selz site does not have a FB pixel...
Amazon remains a potent force in publishing, obviously. But if you CAN build your own base -- as I have in certain genres -- and if you ARE doing your own formatting with Calibre, etc., then either one of these options is going to net you considerably more than Kindle via amazon.
FWIW. As always, do your own due diligence.