windows96,
Every pool of people generates a different mean rating and a slightly different distribution of ratings. It's inevitable: players come, then leave; playing conditions are different from those of OTB; the strength of players that come in and leave are different. The reasons are legion. Not only that, but a player who is strong in OTB may play with reckless abandon here sometimes, and seriously at others times.
A little study I conducted a while back, however, suggests that over the range of ratings typical of the average adult USCF member - ratings here (in Live Chess Blitz) are not all that far off from OTB numbers.
Your mileage may differ, perhaps, however.
Hello.
I have noticed that the ratings on this site are somewhat inflated, i'd suggest that working on functions for making ratings here like in real life otb. It would greatly make this site more popular.