That's funny, because this Topic is over two years old, and this fandom has grown until now, but you can see this really good on the number of visitors of Bronycon,
100, 300, 850, 4000, 8400, 9607 and this year 10011, first it was an exponential growth, and now it's still growing, but the growing had slowed down, maybe it is at the peak, after the peak it will shrink exponentially, you can see this kind of development in many other things too, like the growth of the world population, and even in biology in the growth of a bacteria culture, but it will go asymptotically towards zero, that means, there will be some hardcore fans, years after the show ended.