"The file is uploaded to a protected folder and from there it is copied to a temporary cache folder?"
What logic is that?
I want to sell music albums of which some are 1 gigabyte each, is this plugin going to be copying those files around on my paid server?
In total I have 240 gigabytes of music albums - try copying those around on my server and my account will be suspended!
Weird logic, Weird idea - Forget it!
Thanks for reminding me to update the description over here. :)