I have used Smashwords for years. It's good for fiction publisher, not quite as good for nonfiction. And it's only for e-books. All the options I share in this post are good for authors who want to publish print books. Today, it would benefit most authors to publish in both formats. I've never used Draft2Digital, though I've heard other authors use it with great success, but it's also for e-books. Another e-book distributor option is BookBaby.

I'm glad to hear about your success. You're talking about 40K in royalties on Smashwords for nonfiction?