Given that you'll never be able to prevent copying, the question is, what can you do to minimize it? What can you do to make consumers happy enough with legitimate use of the system that they'll be willing to pay for it?
“There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there.”
“I love to look at The Graduate, or Lawrence of Arabia, or things I had nothing to do with. But you could not get me to go back and watch movies that it was a privilege just to be around them when they were being made.”