That seemed like a pretty high number for a single apartment building in Washington D.C.
For what it's worth, I'm incredibly happy with it so far.
If we assume the 3x10^6 sales are all US (false, but good to some order) and estimate the US population at 300x10^6, then the expectation is roughly 1:100 that a random person will order a unit. Conditioning that on socioeconomic factors should yield a reasonably high probability that if you ordered one, so did several of your neighbors.
As a contrast, I was the only resident who had an iPad 2 delivered during the launch weekend.
There are 300 apartments in my building, and I'm actually in the minority demographically (my building is ~ 1/3 diplomats, 1/3 graduate students, and 1/3 "other"). I suspect for the "other" though, that we're all at least in a moderately similar socioeconomic bracket.