I am currently involved in 2 artists cooperatives, and the benefits are palpable. Gallery space becomes more affordable and you are allowed a certain amount of political stature (ie; creative visibility and clout). Now, a photography coop makes much more sense in that it draws more attention to photography as a viable art form (read f64) and as mentioned above gets more money invested in important ad space. There is a book out there titled "The Business of Art" (sorry the author's name escapes me) that outlines the importance of garnering a broader base with other artists in gaining gallery attention. I am all for this idea, regardless of whether my work fits the standard here, and I will continue to pursue coops as a method of putting more of my work in galleries.