Launch-day in-store availability would have been a nightmare. Other products may have seen comparable volume, but had very little variation: black/white, 16/32/64GB, CDMA/GSM/WiFi ... and that was it (and that was a lot to juggle the first few hours). Here, we have small/large, sport/regular/edition, silver/gray/gold, 1-3 sizes per band, lots of colors per band, lots of bands, ... resulting in a LOT more combinations which means very few available for each combination which means people getting annoyed that they stood in line that long just so most couldn't get what they actually wanted. Too much potential variation in what each customer wants, not enough ways to package enough desired variations without actually assembling on the spot (and still not having enough components).