It may be in the interest of content providers to provide refunds. Although I don't have any studies that say so, I suspect users will more willing to purchase

It may be in the interest of content providers to provide refunds. Although I don't have any studies that say so, I suspect users will more willing to purchase content if they know they can get a refund. Perhaps optional refunds can be baked into the protocol, so content providers can decide if they give refunds, and users can decide if a purchase is worth the risk.