Fiction and nonfiction book sales are like horses and zebras. They look kind of alike, and their related in their DNA, but they ain’t nothin’ alike.
I don’t bother trying to sell my nonfiction. It should be an enticement to something bigger. Let’s say you self-publish a nonfic ebook and make $15 every time you sell a copy. You sell 1,000 and you’ll get $15k. BTW, unless you’re a name, you’re not going to sell 1,000 copies at a price that will net you $15 each.
Buy a case of them and write off the cover price. Give them away at a free talk and convince some people to take your online course for $299, convince a handful to join a mastermind at a giveaway price of $1,200 for a year, and take in two personal students who pay you $10k each. You’ve made a crap-ton more money, and converted a lot of other people who will sell your services (not your book) for you. Which is worth more? For each step in the process, you have a chance to convince them to move up to the next level, and make you more money.
That said – sure, you can sell physical and digital copies of your nonfic books. Sell them for full cover price and the reader gets a free online course or something for free. Use nonfic books for exactly what they are – a sales tool.
Fiction. ::sigh:: Write a series, and get the first three volumes out ASAP. First one is $0.99, second is $2.99 and the third is $4.99, which is where all the others are priced (at least). Each book is simply a sales tool for all your other work. 1st book has a msg at the end – “Buy vol 2 for only $2.99” Vol 5 has the msg – “Get all the books in the series for only $49 – I’ll email you each volume as it’s published.”
Always ALWAYS be building an email list that you control. You use emails to build relationships with the people on your list. Once you develop a relationship, you can market your stuff and other peoples’ stuff to them.