your psychology, your interaction, and the relationship you have with your avatar. We get so many requests, actually, that we usually have to pass -- we're not smart enough to choose which ones are legit and which ones aren't, and if we posted them all, we'd do nothing but post requests for survey answers all day. But I like the way alckly has done her research over on WoW Ladies LJ: she posted a question about WoW jargon, and you can see everyone's answers right away.
We definitely have lots of jargon to go around, from LFG to twinks to PuGs and a lot more. But what's most interesting about all of these answers, to me, is the way it spreads. There's a little bit of Googling and research going on, but really it's a very social thing -- you see "wtb" in the trade channel, and then you ask someone you know what it means (rather than looking it up somewhere else). Thus, definitions of the terms are very organic: "pst" could mean "pssst, here's a whisper" or "please send tell," and yet because they both mean the same thing, both meanings propagate. Likewise, usage tends to be a very social thing -- the person who types "LFG strat need heals" won't type "would u like 2 go to strat?"