Ask HN: How can I encourage insitutions to update book lists?

I'm working on a project involving institutions uploading book lists to a website to be accessed by the public. (You can see which books are where, like your local public library website)<p>Besides for the incentive of a free and easy 'inventory' list, how can I be sure that users will be updating their book collections as books come in and 'die'?<p>Creating an initial inventory list is moot if its not updated. Users might not have time or reason to occasionally update. I'm not talking everyday, just every so often. I'm looking for a powerful reason for them to make a point to do I on their own besides for my email reminders which they can simply ignore.<p>Thanks.