From the Donate page:
"Our 100% Happiness Guarantee
We want you to be proud to be a supporting member of our site! Should you ever become dissatisfied with our site, at any time, for any reason, please allow us to promptly refund your entire donation, and absorb the payment fees, no questions asked. And you are welcome to keep the lifetime license key in case you decide to try one of our programs again in the future."