Third-party services have been experimenting with various ways of measuring Twitter reputation for some time now, but it turns out that Twitter has its own "internal scoring system," and every user has an official "reputation score."
Twitter hasn't made the algorithm -- or the scores themselves -- public, but former CEO Evan Williams at the Web 2.0 Summit, though he didn't disclose specifics, he did share that each Twitter user has a reputation score, which the company uses internally as part of its "Who to Follow" formula. That score may eventually become part of Twitter's public-facing features, says Williams.
Reputation scores, and influence in particular, have become trendy subject matters in today's social media world. Startup Klout has developed an entire business around scoring social influence. A Twitter user's Klout score, for instance, could determine whether he or she gets special treatment from an airline or hotel.