I’m going to answer as a writer. Ebooks are a perpetual revenue stream and it’s stupid not to have them. There will always be new people looking for your book. If you aren’t making it available to them at a reasonable price where they can find it, they will still get a copy one way or another. They will buy used or they will download. They’ll get the book, but you won’t get any money. Ebooks now account for over 70% of new book sales, so the idea that everybody will go to Scribd or filesharing sites and nobody will pay is bullshit. If you actually look at the download tallies on ebooks on torrent sites, you’ll find that most eBook torrents get one to eight hundred downloads in a period of about five years or more, not counting corporate bestseller titles. That’s several hundred dollars in royalties at best - far less than the price it would cost to run a promotion and advertising campaign, which would inevitably require you to give away free copies anyway.
The price it will cost you to take the document file from your already-edited-and-formatted manuscript, drop it into Calibre, and convert it to epub - Free. That file’s just sitting on a disk somewhere anyway. Why do all that work formatting and editing just it stuff it away forever when it could be making you money?
Amazon will give you a 60 to 70% royalty, depending on how you price. And they’ll promote your book to millions of people internationally who’ve never heard of you but buy the same kind of material. You reach more people than you ever could with a website, Facebook page, etc, and it’s with a retailer they already shop with.
Some people are pulling 20,000 to 80,000 a year in eBook royalties on Amazon alone. And nonfiction titles can sell at higher prices - ten to twelve dollars instead of the two to seven dollar range fiction writers have to stick to. (Plus, barely anybody knows this, but you can trip out your book page with graphics and special formatting - you could totally replicate the look and feel of the BALG site in your book description, right down to the crazy demon pictures.)
Of course, you could sell the ebooks on your own site at a higher price, but I think that would be a mistake. This is dead material. The best thing it can do for you is direct new people to your site to buy your newer products. It can give you high visibility in a mainstream marketplace and put you on a footing with the “big” occult publishers, right there on the same virtual shelf. Old books bring new readers, but for readers, psychologically, a book that isn’t sold in the book store with all the other books isn’t really a book.
Here’s what smart publishers and distributors are doing now that everything’s going digital - you release a “Limited Special Edition,” in advance of the digital version. The Limited Edition is just for people who really love your particular product and want something extra special to show off on a shelf and always have handy. The digital edition is for the broader audience who just want it portable and on-demand and don’t need a perfect physical copy. This is becoming just as standard in book publishing as it is in music and film distribution. There are several indie publishers that do NOTHING but $300 tripped-out limited editions of forty-year-old pulp novels that are still in print and available as ebooks, but those limited editions almost always sell out in pre-order.
A lossy mp3 doesn’t replace a limited edition 3-CD box set with gorgeous artwork. What’s important is that people will pay for both. Nobody says that musicians should be deprived of mp3 royalties because some people paid more for the box set. Those people paid more because they got more. A physical object is substantially more than a compressed file - especially when the object in question has talismanic properties, and substantially more money should be paid for it. You pay more, you get more. If you don’t think you got “enough,” then you wait a few years and sell your ultra-rare item on eBay for three times what you initially paid. How “fair” does it have to be?