She's one of the pioneers of being hot for a living on Instagram and it's not hard to see why... especially from a rear vantage point.

Jen Selter is one of Instagram's original stars, and she hasn't slowed down one bit. She has surpassed 12 million followers, and by the time we check back in with her next time, that'll probably be double.

And it's all because of her butt. Well, kinda. Her rear end definitely got her noticed, but she was a workout champ long before that -- how do you think she got those perfect glutes in the first place? And she hasn't just sat back passively, basking in her internet fame. She's been makin' moves, creating fitness apps, self-marketing...all in the name of BOOTY POWER!