Maybe just something simple thrown into MySQL or even Redis and you could make it manually updated via users who visit the site and want refreshed data (so no cron jobs or massive nightly updates--individuals clicking a button to update their own stats). The users who sign up would then have a reason to come back and refresh their stats which creates sticky engagement, etc.

I really think gamification is a huge part of what Steemit/STEEM is missing to incentivize beneficial community behavior. I've liked @arcange's efforts with https://steemitboard.com/ and I hope we see more things like that. When it comes to human motivations, what is incentivized/gamified is what reproduces. We're seeing this with self-votes and voting bots. Instead of trying to fight that directly, we could create new, non-monetary incentives (community prestige, reputation, influence, conference speaking opportunities, promotional space, etc, etc) rewarded for those who bring value to the blockchain community (even value without a direct monetization). The cool part of that approach is it, ultimately over time, equates to monetary value by helping all STEEM holders and incentivizing behavior we as a community want over what is just good for the individual at the expense of the group.