But those have all these fancy Internet words I don't understand!
or do it the hacky way, make a zip file put a random password on it, then upload it to dropbox or something to host files then when people want the file password, they pay you, make sure you get them to sign a message with there address so you know someone aint trying to pull one of those "I downloaded but lost it can I get the password again" type scams.
I must say, this is sounding pretty good. If nothing else, I'll have to do this.
as another idea just to make it more secure, send the zip to one person then after that person confirms they downloaded it, remove it then change the password, so they can't share, but you have to make sure the zip password is very random and long
This keeps them from sharing the original link, but then they could simply share the zip file (with the password, or even extract, re-zip and share that). So it really doesn't resolve that problem.
Once the person has the file, they can share it, no matter what, but it does solve the issue of preventing it and deterring people from doing it. He wasn't going to be sharing it to a 1 million people, only a few so I think that would work just fine. Unless of course you have a better idea, but this thread is old so I don't know why you feel necessary to comment on it.