I think we sometimes get too in love with the idea that the tabletop gaming industry is small. Makes it seem more cozy and personal. And compared to other entertainment industries (movies, pop music, video games), it certainly is, but size is relative. If you consider that most mid-size towns have at least one FLGS (Friendly Local Game Store) or more and how many millions of tabletop gamers are in the US alone . . .
So, yeah, the industry is big enough for a professional association and a magazine!
I teach astronomy (among other things) to middle-school students and try to get them to understand the concept of scale. The planet Earth, compared to Jupiter, is very small. But, I wouldn't call Earth a "small planet", there's a lot of folks living here! And of course Jupiter pales in size compared to the Sun, which is only a "medium-sized" star, one of billions and billions in our galaxy alone . . . . (read that in Carl Sagan's voice).
EDIT: Sorry to get all teacher-nerdy on you all!