At Teambox we have a comparable feature set (tasks for teams and files) and we moved to freemium about 2 years ago. While the usual freemium math applies (most

At Teambox we have a comparable feature set (tasks for teams and files) and we moved to freemium about 2 years ago. While the usual freemium math applies (most users are still free), our customer's response has been phenomenal and subscriptions are now a sustainable business.