Electronic book sites. Here's Tim Reese's.
In the early 1980s, I founded a publishing company starting with an electronic newsletter (available via TELEX, and some old online non-Internet services). For reasons not known to me, Mid-East Business Digest is still being downloaded and I still receive royalty checks for material written in 1983. Some of my distributors have made my ancient writings available on pay web sites. I am not suggesting this as a business model but draw your attention to the fact that information and analysis are extremely durable and (to someone, somewhere) useful.
I wanted to get into book publishing in 1982, however I knew that the book sales cycle was inordinatey long, which meant that the information feedback cycle would be painfully extended. To learn book publishing quickly, I entered the music business in which the manufacture / sales / returns / payment cycle was identical but highly compressed. In book publishing one project might disclose its secrets in 18 months. In music I got project feedback much faster and learned the wholesale and retail distribution on the QT.
This experiment took on a life of its own when my company's first releases more than paid for themselves; the temptation to continue here was thwarted, however, once "the industry" decided that the dual record and cassette release format needed a third format, the CD. (We indies viewed the introduction of CDs as economic warfare.)
I say all this to make a simple observation. Considering the amount of hassle shouldered by some of my fellow record company owners in the mid-eighties in issuing every release in no fewer than three formats - not counting singles - I am completely baffled as to why book publishers cannot create and maintain an e-edition of every hardcopy book they release.
What the hell? Every manuscript is submitted as an electronic file and it makes its way through the book publishing process as an electronic file!
What is the problem that keeps good work from staying in print (via e-editions)? We have actually gone through controverisies in publishing with contractual e-rights between author and publisher. Have they not been settled?
The best outcome right now seems to be one in which rights to out-of-print editions revert to authors, and authors republish e-editions.
Tip of that hat to Tim Reese for blazing this path.
[p.s. If you have not read his work on the Maryland Campaign, I am reasonably sure you do not understand it. I say that having been humbled reading Tim's books.]