I like mutual follows as a metric. I think it's one of the more important ones when you're looking at a static graph of users following users, which I'm assuming you have in some form but you can correct me if I'm wrong. But I was wondering why it was 1.0, rather than something smaller because not all my follows/followers are mutual. And is the metric outgoing mutual (mutual follows / who I'm following) or incoming mutual (mutual follows / who's following me)? Maybe both could have some use, because "reciprocity" is a broad term.