Libraries aren't exactly convenient for normal consumers.  To go against your video game and cd relation to a book: Video Games are targeted to a very large market and the majority of games today tend to offer much more than 2 or 3 hours of entertainment especially if you take the case of online play; CDs are in a market that is surrounded by piracy and yells of corruption but to take the price point a cd usually offers much more value than 70 minutes of entertainment and one popular way to consume music and purchase it is through itunes which does indeed offer lower prices for basically the same content.