That it is an American console has very little to do with anything. After all, no one is playing 3DO, Apple, or Atari consoles.
Having Netflix first was huge in the US. I have several friends who bought one for that reason. Once the PS3 and Wii could do Netflix, every device could do it, so it didn't matter as much.
Having the best online infrastructure and the most people online certainly hasn't hurt either. Cross-game chat is another related big deal.
This is speaking anecdotally, but online doesn't seem as big in Japan (even though their Internet speeds are ridiculously fast). All of the used games I have purchased with an online pass (DOA5, TTT2, etc.) the online codes have all been unused.







