Sites running Paid Memberships Pro use it to:
Manage professional organizations with thousands of members.
Get paid for e-learning and digital courseware.
Accept recurring payment for content, podcasts, video, and more.
Create private social communities for unique interest groups.
Develop robust directory or listings sites by topic or region.
Offer product subscriptions or members-only product discounts.
100,000+ active installs.
Recommended by businesses of all types.
I am not a developer, but I found it very easy to set up different membership levels and membership charges. PMPro is very flexible. I would recommend this application (plugin) as a perfect solution to website owners building a paid membership clientele.