It's been a couple of months now but yes i'm on official brony. I'll admit that I was skeptic of mlp:fim but a few things convinced me.
1) The charecters-For each charecter in the show their is always more to them than meets the eye. For example take Flutershy; she's shy, kind, etc... BUT is literally able to stare monsters into submission. They are also pretty easy to relate too. Take Twilight Sparkle in the first episode; she (quite sensibly) puts side making friends for larger responsibility. This is what actually sparked my interest. Then Twilight learns that even though it is commendable to try and solve problems by your self, its much better to have friends to rely on.
2) The morals-Even though i'm a college kid I can still learn a lot from this show.
3) The style- the animation is pleasant to look at, and the music is admittedly catchy.
4) The Fandom-From fan art to fan-fiction their are several branches of creativity involved with the fandom. You get awesome fanfics, dubstep, memes just to name a few ways bronies express themselves.
5) The mythology-Much like Lord of the Rings, MLP has a fascinating background and history to it. Its easy to get swept into their world.
I also made an account on fimfiction.com
my user name is NovekBrony.
till the wirld sets on a world without mlp...stay gold Bang!