Why start with a full-blown ruby app for something like this? What is the drawback to starting simple with a git+markdown based statically generated site?
With writefully the idea is you get real business objects you can build business intelligence into. So for example I only want users who buy a piece of content to be able to view it, I can do that with associations or some sort of logic to detect who bought what. It's difficult to do that sort of thing with static sites.