Has mixpanel made it easier to keep track of a customer when they transition from anonymous browser to registered user? When I last looked into it, you had to capture the random cookie token associated with that user when they were anonymous, store it in your database when they register, and then present it to mixpanel as identification forever after.

We went with KISSmetrics for a couple reasons, but one of them was that whole process was much easier: just a simple identify() call with an email address, and KISSmetrics will associate the previous anonymous token with that email address automatically, so you have a complete history of that user.