I would like a website where I can publish some content and charge a subscription fee to customers, as this content updates intermittently. The content is a collection of regular Google Docs documents, which can be published as HTML and embedded in a page, for instance.

Subscribers pay by credit card (Netopia) and can choose between 3, 6, and 12 months plans.
They can register for a Free Trial and have access to a limited portion of the content.
Tracking user visits is important, to know where they'd lost interest if they didn't subscribe.

If you have any relevant questions, I'd be happy to respond in about 2 hours while available, between 5 am - 7 pm GMT/UTC, Mon-Sat.

Thank you!