I clicked the link and it says free till 1/31/16 for me after I registered
scroll down until the terms where it says
How it Works read that section and underneath in the terms it clearly says
"*Exclusions apply. This is an exclusive offer offered to eligible PayPal account owners. With this service you are eligible for up to 11 refunds on your return shipping costs from
February 1, 2016 through to December 31, 2016 and may receive refunds of up to $30 USD per claim. PayPal reserves the right to cancel or modify part of or this entire Offer at any time without notice, for any reason in their sole discretion. See full terms and conditions."