In 2015, we believe we'll convert 3% of active users into paying subscribers at $60/yr. For additional reference, the 81K subscriber adds represents 15% of our projected Power Users (5+ deck creators).
For reference, Evernote is converting 4% of users (34M users, 1.4M paying). Additionally, their ARPU for iPhone is $1.79, iPad $2.18, and web $1.81.
http://techcrunch.com/2012/06/19/evernote-by-the-numbers-34m-users-1-4m-pay....
In 2016, we believe we'll convert 2.5% of active users into paying subscribers. This represents 10% of projected Power Users.