I've been studying this for some time and found some quite extraordinary things. Some programmers have made $100,000s out of writing the right program. Marketing is not an issue for them, it's quite easy to sell it.

On a similar topic. I have come up with a method of locking a 'software container' (like Adobe's PDF reader but something else that would have to be custom written) to a PC so that the document CANNOT under ANY circumstance be copied to another PC and be opened. The method is quite simple but it needs to be carefully programmed to prevent hacking.

What this means to eBook publishers is that their documents can be copied with impunity but can never be read away from the target computer.