Monthly Subscription Plan vs Annual Subscription Plan?
pvg: I think it depends more on the complexity (conceptually) of the product and the cost. A user might be more inclined to commit for a shorter trial period and test the usefulness of the premium features - for consumers, 'cost of a latte' seems to be a much easier decision to make than $50. There are also other parameters you can tweak, the first one that comes to mind is the utility of the free offering, especially for a community site - more users means more network effects, more community participation and more opportunities for conversion. Right now your free offering seems to be drastically more limited than the pro account and that might be something you could play with.