Bringing this back from the grave…. good idea!
Nice idea but it being digital would be a must since they probably can’t start sending those gift cards all around the world.
It would be great! can be used by authors to promote or say thanks to their buyers, i.e. an author with a file with more than xxxx sales can made a contest on their site, product page or social media.
Like W. Disney used to say: : “If you can dream it, you can do it”