How to enforce the division between free and premium? I guess you choose a natural line, that doesn't need explicit enforcement - like 300 photos on flickr. Th

How to enforce the division between free and premium? I guess you choose a natural line, that doesn't need explicit enforcement - like 300 photos on flickr. There's no fuzziness about whether you have >300 photos or not, and the consequence of the older ones disappearing is gentle and non-punitive. You can do the same thing with a software license, by having versions with different functionality - feature subset, capacity limits. Some companies have a "community" version that is free. He's also talking about models where you benefit from the "free" users - for selling software, bug reports and feature requests are valuable information, for product quality and market needs. One danger is that if you whet people's appetite with a free version, you can be priming them as fuel for a free/open source competitor! E.g. Photoshop enabled The Gimp; Unix vendors enabled Linux. This happens if they really need/want some feature in the premium version, but it's too expensive for them. Maybe this concern doesn't apply to retail/consumer subscriptions because they aren't expensive; definitely not worthwhile anyone creating an open source competitor in the first place; and not targeting programmers (who could create a competitor).