A lot of books, especially fiction, you can finish reading within 14 days.
I was never made to feel guilty about borrowing those books from the city library, returning them two weeks later and never buying them. When did the standard change?
An App Store is not a library any more than your local Borders is. At least the copy of the book that's in the library was bought and paid for somewhere along the way.
Libraries already do lend eBooks, and they do enforce scarcity. You can go today to check out an eBook only to be told that it's not due back for another two weeks.
I was never made to feel guilty about borrowing those books from the city library, returning them two weeks later and never buying them. When did the standard change?