Here's what we have for participation rates in the #Change11 MOOC this far.
'Persons' are people who have registered for the course. The gap between persons and subscriptions is the number of people who signed up for the course but unsubscribed to the newsletter.
'Subscriptions' is the number of people subscribing to the daily newsletter.
'Feeds' is the number of blogs submitted by course participants and harvested by the feed reader. It includes active feeds only.