I just face a case, normally when we upload a delivery with images it has a water mark, but what about the zip files.
Recently one of my frnd have the case he send files in a zip, the buyer got them and then cancel the order sayng that he didnt like just cancel no other reason.
so i thought he got the files then do this, if they were water marked or some other option for many files. then it wll be great.
Also some time user got the zip files and forgot to mark the order completed and to rate and feedback because he got what he want, if they were water marked then then he must have to mark the order so he can have the orignal files.
So there should be somethng for the zip files security.