Where to leave your discarded books

Ponder this from Tyler Cowen:

"One radical option is to leave the book, well...in a bookstore. Most likely, the book will be sold. If you bring it to the counter they will be puzzled but I suspect will be willing to ring it up and punch in a code.

Of course now the book has a price, which can restrict the chance it is ever read. But the chance of it getting into the right hands -- the high-valuing user -- has gone way up. This is a testament to the role of middlemen in a capitalist economy. The book is probably worth more to the world at full price, in a bookstore, than lying on a bench for free.

So now you know where to leave your discarded books."