A survey of non-pony fans — I am assured that there are such — yielded these interesting conclusions:
1) Exposing people to episodes of MLP does NOT automatically turn them into Bronies or fans of MLP
2) People who MAY develop into fans DISPLAY a distinct set of characteristics that correspond to a curious, open and less traditional approach to life
To contribute a single data point: two weekends ago, I exposed someone — Future Daughter-in-Law — to an episode. (Specifically: “Call of the Cutie.”) I also pointed out where on Netflix the other 64 episodes could be found (in the obvious place), and noted that I’d actually written some fanfic.
Results: Not clear at this time, though somehow she read the entirety of The Sparkle Chronicles. Based on point 2, however, I am hopeful, if only because I’ve seen her bookshelves, and they rival mine for sheer variety.