Pending records are created whenever you hit the order page.  This is how the system tracks customers through the ordering process, and is how you can track abandoned carts and PayPal transactions. Pending transactions with no customer data are instances of abandoned carts. Here's how this happens:

The customer clicks on the buy button -> Nanacast creates a pending instance of a subscription with no data in it yet, and directs to the PayPal checkout form.

The customer sees the PayPal checkout form requesting name, email address, etc.

At this point, one of two things happens:

A) The customer completes the form -> The transaction appears in PayPal, and when PayPal transmits the IPN for the transaction, including the customer name and email, Nanacast updates the info on the pending record and changes the pending status to subscribed.

B) The customer does not complete the form -> There is no data to capture, no transaction has taken place, so no transaction appears in PayPal, and the pending status remains.