[rhc2104]

Facebook's user id system is not linear (although it used to be so on a per-school basis)

http://www.quora.com/What-is-the-history-of-Facebooks-user-I...

[feldmanr]

Interesting. We had some idea it wasn't totally linear but thought that the numbers (particularly for those that joined after college) had some validity. Do you have any thoughts on how to come up with a better algorithm given Facebook's ID system?