Three.
We were on a school camp and we were in a chalet and we had a TV with sky and they were playing MLP all day on a Chanel. As the closet brony I am I was like "Wat, We should watch it" so I really converted 2 and a half, Two watch the show now and have merchandise (Quicker than ME), 1 kind of watches it occasionally (but he clops :l (thank god I'm not in his class anymore)) and when we had free time they always watch MLP. I'm so proud.