Paypal recurring payments I'm currently using Drupal Commerce and the Commerce PayPal (https://www.drupal.org/project/commerce_paypal) module in order to allow my users to purchase items. That said, some of the items require that my customer be charged every month. Is there a way to store credit card data in order to run recurring payments (Commerce Recurring doesn't seem to be compatible with Commerce Paypal)? If I'm not mistaken, the documentation states that PayPal doesn't include the option to run recurring payments? Is there another module I can integrate in order to allow this?
We never implemented PayPal's direct recurring API, though there should be a patch in the queue to try out if you wanted. The thing to check will be real-time notifications of recurring charge failures and whether or not there's a user interface allowing the customer to cancel. Since it's PayPal, there very well may be from within PayPal itself.

PayPal does offer the ability to create Billing Agreements that you can charge against at later times, but while we included the ability to create Billing Agreements via Express Checkout, it was never fully integrated into the Commerce License Billing suite that we would normally recommend for recurring payment management.

In short, with PayPal your options are limited. If you are able to make use of Commerce Braintree instead, which is a PayPal company, I'd advise doing so, as that module offers a direct integration with Commerce Card on File (and therefore the license billing module).