Controlled Digital Lending’s essential position is that it’s fine for a nonprofit like the archive or a library to scan a print copy of a book it owns, then lend that digital scan out on a one-copy-per-one-user basis. The print copy is to be unavailable while the digital copy is loaned, meaning that only one copy is out at a time in any format, and an author or publisher has the right to opt out of this by asking. Many rights holders have, indeed, asked to opt out because, as they see it, the user of a loaned digital copy of their book has paid nothing for that loan and this means copyright revenue has gone unpaid. – Publishing Perspectives