And I came super late to the fandom, myself. I only started watching Buffy after Firefly came and went. Surprisingly enough, that was the fandom (although it was more of a Joss Whedon fandom than a Buffy fandom) I was a part of about 4 years ago when I came back to fandom. You'd be amazed where you'll find packets of fans that are still excited about fanfic.