My data seems to be a bit of an outlier (entry #294 on the Tesla Estimates tab), and it may or may not help with the understanding of how Tesla is prioritizing.
I'm a non-owner and pre-ordered 3/31/16 at ~12:10pm eastern time, however I am taking delivery in my home state of Oregon. My First Production estimate has always been ahead of all the other east coasters that I've seen, and presumably even ahead of the folks who were in front of me in line from what I can tell. I believe this is because my Tesla account has my Oregon address for delivery location.
My original First Production estimate was Oct-Dec 2017, then bumped to Nov-Jan 2018, and most recently it now says Feb-Apr 2018. I've only seen one or two other non-owners who share this time frame on reddit, and even the 10:05am California reservationists seem to mostly all have Mar-May 2018. I'm not sure if this helps at all, but I believe it is the combination of delivery address and my reservation being the equivalent of ~9:10am west coast time, putting me ahead of most of the California reservations. If this is true, I may be one of the first non-owners to get an invite? Doesn't matter too much unfortunately for me as I'm deferring for the performance model, but we'll see what happens.