Publiczr has a sign up form for newsletters that integrates with most of the common newsletter services. You can easily keep track of all newsletter subscribers directly in Publiczr.
If you want paying subscribers, a payment plan can be set up, where you decide the price, the renewal period and whether you want to give people a free trial period in the beginning (e.g. first 14 days).
Paying customers should of course be granted special rights, and the most common ones are access to premium content, an ad-free experience or the possibility to comment on articles. All of this can be managed directly in Publiczr.