That common factor enabled YCHT/YMSG which allowed for ad-hoc communication in and out of those silos. That friends list could chat, play sports, send emails, play chess, probably other things (those are all I did). It wasn't formal in that there wasn't an activity stream (as far as I remember; I didn't work there and I was like 13 at the time) in each silo, but people I met playing chess moved to chat and then to other games.
