<intro-rant>So you're running a Drupal site. The site's performance is decent and there's nothing really to complain about except at some point your marketing team or marketing person comes to you and you end up having a conversation like this:
Them: You know we really love the share widget thingie we got on the site and all the stats that it comes with but which of these services do our people really use?
Them: We would like them to log in using those services instead of having to create local accounts. You know, make it easier. I hear simple sign on is the way to go these days!
You: Sure, there are a few modules out there that we can try out. There's this thing called Janrain Engage for example....