As pieces of information, you could copy a book as many times as you wanted, or in the case of libraries, loan it out that many times. This article labels publishers as “greedy” for limiting the number of times an e-book can be checked out at the library, but I’ll bet there’s more to it than that. I understand the point that libraries could preserve books forever, but there’s all sorts of stuff wrapped up for authors too in what constitutes “in print” vs not. My hope is that some publishing types might comment with opinions here.
But why can only one person borrow one copy of an ebook at a time? Why are the waits so damn interminable? Well, it might not surprise you at all to learn that ebook lending is controversial in certain circles: circles of people who like to make money selling ebooks. Publishers impose rules on libraries that limit how many people can check out an ebook, and for how long a library can even offer that ebook on its shelves, because free, easily available ebooks could potentially damage their bottom lines. Libraries are handcuffed by two-year ebook licenses that cost way more than you and I pay to own an ebook outright forever.
Ebooks could theoretically circulate throughout public library systems forever, preserving books that could otherwise disappear when they go out of print—after all, ebooks can’t get damaged or lost. And multiple library-goers could technically check out one ebook simultaneously if publishers allowed. But the Big Five have contracts in place that limit ebook availability with high prices—much higher than regular folks pay per ebook—and short-term licenses. The publishers don’t walk in and demand librarians hand over the ebooks or pay up, but they do just…disappear.