Differentiated Services: Sometimes there is a need to enable different services for different users. A good flag system can enable paid customers to see different features than unpaid users see. Many membership levels can be implemented by associating a set of flags with each one.
Should this be a separate system as well to maintain customer feature permissions? Seems that this would need to evolve very independently...
But the other pattern here is that it might be good to have the same set of features and available treatments for each feature across these needs: global feature enablement/kill switch, a/b testing, customer-level feature permissions/access
