I have a Wordpress based magazine site that's about 14 months old and have never got around to really investigating the best way to grow my RSS feed email subscribers. Any ideas on how to get them to sign up? The site is updated fairly regularly, usually weekly or longer if I'm busy. It discusses writing and related topics. It's not exactly a small niche!

I ran a book giveaway recently and subscribing could be counted as an entry. That wasn't that successful a tactic. I should add that I won't resort to having people sign up that aren't interested in the subject just to add numbers. I get plenty visiting via Twitter and Stumbleupon. They just don't sign up when they are there.