That passage though does provide some more details: "For a classic work, which readers were likely to check out steadily for years to come, a library might purc

That passage though does provide some more details: "For a classic work, which readers were likely to check out steadily for years to come, a library might purchase a handful of expensive perpetual licenses. With a flashy best-seller, which could be expected to lose steam over time, the library might buy a large number of cheaper licenses that would expire relatively quickly." At least perpetual licenses are an option.