On October 22, we changed the format of one of our platform-wide cookies. The conversion process is pretty simple: we check for the old cookie, use it to create the new one, and delete the old. This happens exactly once for every user on their first visit since Oct. 22 to any Kinja site. The graph below shows the rate of conversions per second we're performing across the app servers in each of our datacenters:
I think this provides some interesting insight into our usage patterns. In particular, that even five weeks later we are still converting about 1 user per second.