Not exactly. Turns out you can sell via Amazon, or you can sell directly, but if you use the undocumented Amazon-only tool to construct your .mobi, you can't sell that directly. And Amazon is now blocking the output of many/all other ebook construction software so you can't use Send to Kindle or email. USB is the only option to load a book.
http://devblog.avdi.org/2014/04/02/why-does-amazon-hate-eboo...