Congratulations on the hit product!
I think a big part of the success is because of diaglo's years of posting about the supremacy of the OD&D: "the one true game".
(snip) There's a large base of gamers who simply never shifted to later editions, but many gamers (including me) moved on to later editions on auto-pilot and didn't (or perhaps still haven't) realized that several edition-shifts have brought the game into a qualitatively different sort of rule-set entirely. (snip)
... playing 3.xE and 4E have better prepared me to run S&W: both of them made me think of what combat actually entails but, rather than relying on the rules (and particularly 4E powers), I can work results into the narrative instead.
Anyway, I hope S&W continues to succeed.