In a recent interview in Online Community Report, the CEO of message board provider ezboard explains their switch from free to paid services, "We've had over 24,000 community subscriptions, 19,000 user subscriptions and 45,000 user donations over that time. This currently translates into monthly revenue in the low six figures, growing steadily at 5% per month." Sounds great; who wouldn't want six figure monthly online subscription revenues? (Aside from Yahoo who need much, much more than that.) But, you must bear in mind, ezboard had to boil these down from 8 million free registered users.

http://www.onlinecommunityreport.com/features/nguyen2