I think the main reasons I kept interest in Charmed is that I started watching long after the show finished and it only took me about a year to watch the whole series (didn't want to watch it too quickly cause I didn't want it to end). Also because I think character development was really good, the sisters' moved on well, and I never lost interest in their lives. Yes demon creativity got a little too similar by season 5 but I wasn't too bothered about that.
I agree that it's awesome that this board has stayed open for so long. I hope that continues!
