I've been trying to think this out for a while, and was wondering what others might be using or what Smith themselves would suggest. 

I would like to, at some point, do subscriptions on my site.  All items are downloadable.  I'd like to be able to expose a link that allows users of a certain roll (ie "lifetime subscribers" or "yearly subscribers" to download any file on the website. 

What are other people doing?  Or is there a "best practices" usage for a scenario like this?