With the ability to set member only pricing and now the ability to set member only products, you have the opportunity to create a private catalog that is designed for and exclusive to your membership.  For example, sell an add-on Wine Club membership to give Wine Club members access to exclusive and discounted wines.

To setup permissions on a product, simply go to the product (either edit an exisiting or create a new one) and set the visibility to "Active Members Only".  This will now allow you to select the specific membership levels that have access to these products.

If someone tries to view a product that they don't have access to, they will be prompted to login.  If they go to the /shop page and don't have access, they will see a prompt to login.

If they are logged in and don't have access they will be sent to /memberships to become one.