It is possible to have expiry dates for membership to groups. And since this is based on groups, you can restrict content to paid members. And when their membership expires, they no longer can see the content.
As of Tiki12, we are missing:
- It would be nice to have an automated way to send reminders. ex.: your membership will expire in 60 days, click here to renew. This should become easy with Notifications Revamp.
- Support for https://www.paypal.com/pdn-recurring