yes, it's worth a try. you'll need lots of luck to really reach the big public, but it's surely possible. you just need a catchy domain name, some loyal members, and a good promoting strategy. but it'll be hard, because you don't have one thing you're specialized in so you can't promote it like for example 'harry potter forum', but you'll just have to say 'catchynamehere forums'. anyways, starting with a few mates is the best thing you can do, as you have a good base to strat from when you're doing it like that.