eBooks for sale
While I've had some luck selling ebooks, I've particularly enjoyed giving them away free. While I was busy doing that, an entire industry has evolved around selling pdfs. The math is simple: sell 10,000 at $30 each and you too can move to Gozo and sit in the sun.
The vernacular of the sales process is fascinating, though. Apparently, many ebook authors believe you need to write pages that are 56 inches long, filled with claims, promises and fake book covers. (and sometimes, as you'll see below, this works quite well). I'm not sure that this, by itself, is the future of the medium, though. I think it belongs to people who find a following, curate information for them, build a permission asset and then write a tremendous ebook at a fair price.
Here are two approaches you might want to look at: