more or less a few bots have helped, promotion, spending of Steemcoin probably helped, then from there it just goes. Aside from the bots, tagging your posts properly helps get it out there a bit, the goal is to get followers that will like your posts based on content but anytime there is a weighted reputation system, there is a cause for abuse of the system but i'm sure SteemIt is aware of this and tweak the safeguards here and there.