In my area ( central Alabama) USPSA is booming! local matches are pulling tons of shooters at every venue (60 at the smaller ranges , 100+ at the bigger ranges).
We ran a small two gun match at our local club, it started out pretty strong pulling around 40 shooters each month. It dwindled down over time, we would only have 10-15 shooters show up. It just wasn't worth the set up time for us. I really with there was a sanctioning body for 2 gun, I think that could really boost the sport. Hell, I would almost quit shooting USPSA for it.
I feel like the cost for 3 gun is just too high for the average person. IMO the initial buy in is high and the ammo/ upkeep is high.