Hi Anita,
You’d need to do two things: Use Custom Capabilities to identify those members who have purchased your subscription product and also funnel members and non-members to the correct signup page: Non-members need to become members when they purchase the subscription product and existing members need to have their existing recurring payment upgraded to include the additional subscription amount.
If you’ve decided to use the Custom Capability called “subscription” to identify those members who have signed up for the subscription, then you’d simply include additional conditional checks within your content dripping code to check if the member attempting to access the content has the “subscription” custom capability.
Non-members would need to signup on a page that uses a Pro-Form or PayPal button configured to assign the “subscription” custom capability, and existing members would need to sign up using a Pro-Form or PayPal billing modification button/form (see Dashboard -› s2Member® -› PayPal® Pro Forms -› Billing Modification Forms or Dashboard -› s2Member® -› PayPal® Buttons -› Subscr. Modification Buttons) that updates their existing payment subscription to include the new total payment amount as well as adds the “subscription” custom capability to their existing account, thereby giving them access to the additional content through the content dripping.