Check out http://quantcast.com/dimensionsmagazine.com to see where Dimensions supposedly stands on traffic and demographics. Some seems to make sense, others does not, but interesting overall. I could sign up for a free account and then embed their code in every page but given that Dimensions has several thousand, I don't think I'll do that.
Also interesting: A traffic comparison between Dimensions, a competing forum, and a large plus-size paysite site.
Also interesting: A traffic comparison between Dimensions, a competing forum, and a large plus-size paysite site.