Whoah. Onstage at Web 2.0 Summit, Twitter founder Evan Williams revealed, when asked by interviewer John Battellea4s‚ &''How do you pick &8216'Who to Follow&',&'' that Twitter has a private reputation score for every user.

According to Williams, Twitter&'s &''science and math people&'' have systems which gauge who you follow and who the people you follow follow and try to find &8216'Who to Follow&' relevance in that overlap. He didn&'t make it clear how individual user reputation score was measured.

&''We might make it public,&'' he said regarding the score, &''But it has to evolve more.&''

You can watch the rest of the talksa4s‚ here.