Facebook kept it a lot simpler: you can just iterate through integers. 1 - 3 have been deleted but if you navigate to https://www.facebook.com/4 https://www.fac

Facebook kept it a lot simpler: you can just iterate through integers. 1 - 3 have been deleted but if you navigate to https://www.facebook.com/4 https://www.facebook.com/4 it redirects to https://www.facebook.com/zuck https://www.facebook.com/zuck and so on. All the original founders are sub 10.