I've started watching Smallville (seven eps in so far) and dabbling in reading Potterverse fic because of my friends who are fans and their enthusiastic squeeing. On my own I probably would never have watched the show or read the fanfic; they just didn't suck me in. I'm like you in that I watched BtVS/AtS pretty much on my own apart from mr. muse and some peripheral friends, and it made me a fan all on its own. I think it's going to take a lot for another show/'verse to do the same, without my fandom friends getting me excited because they're excited.

But where are the baby stories?! Don't tell me you've grown tired of the poor child already!