We use feature flags for entitlements and experiments at $work, it's all accessed through a consistent `hasFlag` API. Granted, our use is pretty straightforwar

We use feature flags for entitlements and experiments at $work, it's all accessed through a consistent `hasFlag` API. Granted, our use is pretty straightforward, you either have access to product $Foo or you don't. I think with usage based billing, like first 100 messages free, or tier one gets 5MB uploads, tier 2 gets 50MB uploads it becomes harder to have a universal API, you end up having to do some manual checks. Still haven't really thought this all out but it's an interesting problem. Edit: also roles can provide entitlements / enable feature flags. So Admin could get every feature, while intern might get only get the analytics_read feature.