is it any different to loaning a book to someone? There was a book in the US ( Secrets of the Ya Ya Sisterhood ) that had almost zero promotion and no marketing from the publishers. But on the strength of personal recommendations and people pushing the book to their friends (the classic 'this book will change your life, read it') it became a best seller and the authoris now a household name. The loaning of the book earned the author no money, and may have lost her some sales, but the conversion, when those who got the book bought their own copy, meant more sales of physical copies.

Cory Doctorow