Take one of the leaders of the pack, Swaylo. That platform uses Facebook data that records the number of interactions you have with others, your posts and the reactions to them, plus your friend network, to calculate a rating of your social influence between one and 10. More than 6.3 million users have signed up to see how they rate, and Swaylo has managed some pretty impressive influencing itself: this month it announced that it was being snapped up by Mark Zuckerberg and folded into the Facebook family.