" 'Ere, mate, wanna buy a second hand ebook? "

Second-hand ebooks...

It does sound a bit like a bad gag or a swindle. My somewhat less than saintly grandsire would have sensed an opportunity - and if you were happy with that, he had some farmland in Wiltshire you might like to buy, and so much the worse if it turned out to be an artillery range. And it's true, to a point: why would you sell an ebook for less just because you've owned it for a while? And if it weren't reduced, why would you buy from some random person rather than from Amazon or Apple? 

What's actually happening, of course, is not the transfer of a physical object, but the transfer of access rights or data. Data don't depreciate, so there's no real reason to discount the product because it's been used. The straight transfer is therefore rather dull: person A yields it to person B for the same amount he or she paid for it, and person B gets the file via bluetooth or similar rather than via Whispernet or broadband download. Um. No measurable benefit to anyone. Or, yes, you'd end up with a market where people would discount in order to make some money back, and ultimately drive down the value of the book. Not great news.

However...

Suppose you could return your ebooks if you decided you didn't want them, in exchange for a given value, to be redeemed against further ebook purchases? You'd never get back the full value - and your supplier might choose to say you could only ever get a maximum of 25% off any given single purchase, so you'd have to bank credit.

And/or...

What if you could retain access to your own book files, but get a similar reward by selling them on as well? That turns every fan of a book into a reseller.

Both of these options have the additional benefit to the publisher that they get to keep selling the same thing in a way they never have before with second hand books. The consumer gets cheaper stuff and the assurance of a virus free download... and of course, the buoyant continuance of the industry, which isn't bad in itself.