Ghost 3.0 now includes memberships and subscriptions.

As of today, Ghost is the first totally independent product out there with publishing<>subscriptions deeply integrated at the core, allowing anyone to build a recurring revenue subscription business.

— Announcing Ghost 3.0

I used Ghost for a while for my blog. Eventually the cost was something that I couldn’t justify and so I switched. However, with Ghost’s new memberships and subscriptions, they’re definitely going to attract the attention of many content publishers.