Customers of the online music label/store Magnatune can pay what they want for albums as long as the payment is within a given price range ($5-$18). On average, customers pay significantly more than they have to. We ran an online survey and collected responses from 227 frequent Magnatune customers to gain insights about the underlying motivations to pay more than necessary. We control for individual response- as well as sample selection-bias and find that reciprocity appears to be the major driver for generous voluntary payments. Being inclined to conform to social norms is a positive determinant for payments around the recommended price ($8).