For another data point:
16473XXX ordered 29/02/2012 15:01
I had given up and gone to bed after about 1 1/2 hours of refreshing a solid white screen.
I see from another order posted that they received 4500 orders in the 1:07 prior to mine. By that time, their regular business was going on, but I'll bet the vast majority of orders were still for Pis.