So that's how you've been levelling up so fast. Did you gain like 500+ followers in a day ?
Here's the history of my xp for the past day: http://gfycat.com/LateOddballGourami
Rockstar diamond is at 1000 followers. Now I'm at 1170, apparently.
Whoa... just found XP and Reputation breakdown lists. This is the site that just keeps on giving :D