The problem with paid is three-fold. We're a for-profit company so don't want to come off as taking donations like a non-profit. Second, we don't want to collect personal information. So we could do something like bitcoin but that isn't exactly low-friction :). Third, it is promoting that it exists. We have a hard problem getting the word out about anything not on the SERP and we wouldn't want to put it there.

Open to other ideas though.