[jenno]

Another option is to put it up for sale for the Kindle (kdp.amazon.com) and at B&N as ebooks. At one point I had 5-6 books on kdp and even made over 4 figures one time. I haven't promoted them at all for a good 5-6 months and still make a couple hundred each month. Non-fiction tends to do well; there are many guides out there on how to rank better for your book (use certain keywords and categories etc) so that could be a good avenue for you. One drawback is that it takes 3 months to start receiving your payments.

[RobAley]

I'll look into that, thanks. It obviously has a much wider reader base than Leanpub where I'm currently publishing, although it has lower margins and more "competition". Of course there's nothing stopping me using both if that looks promising. Is there any specific guide for ranking better on kdp that you would recommend? I've just found a couple via Google and they seem to have conflicting (and slightly inconclusive) advice.