I am not sure if this is relevant or even useful, but I will throw it out here anyway.

What about a "below the fold" subscription where some teaser content is free and then hits a paywall. This could work for video and audio content too, so could be leveraged by @threespeak and the like.

Subscription pools where a subscription community collects its own pool (some percentage perhaps) of subscriber funds that get distributed to content in the community based on various usage metrics)

Subscriber pools, where a user can charge their account not just to access content, but also to add additional value to that content, like a tip that comes from their subscription fund. For example, where their subscription gets them a second-layer token that can be used in the community that is backed by the subscription itself and can only get gets distributed to the approved users and commentators etc.

Stats on individual users and the community in general. Metrics are great feedback for users and feed into gamification models.

Not really what you were asking for, but hey, it is something :)