Henry
Autoexreginated
apparently, der Kluge, the answer is, "pretty darned common occurance." I have one guy whose intro came through a combination of Neverwinter Nights and Magic the Gathering (the card game version). He started with computer games, started playing only Magic with our group, and then got curious enough about all the D&D humor and recollections we were throwing around to give it a try. He's recently DM'ed for the first time, and is one of our most diehard members, now.