Making “Freemium” Work @ HBR
"... freemium—a combination of “free” and “premium”—has become the dominant business model among internet start-ups and smartphone app developers. Users get basic features at no cost and can access richer functionality for a subscription fee...
...free features are a potent marketing tool... monthly subscription fees typically charged are proving to be a more sustainable source of revenue than the advertising model
... freemium is more successful than 30-day free trials or other limited-term offers, because customers have become wary of cumbersome cancellation processes and find indefinite free access more compelling..."
New Research Helps Find The Perfect Strategy For 'Freemium' Business Models @ Forbes
The Freemium Model: What’s All the Buzz About? - Online Marketing Institute
Freemium open access publishing learning to let go @ SlideShare