Like someone said before, testing for slippage and out of sample data are your next steps. It is not impossible to create a system that makes money but it isn't easy at all. Ive had a lot of systems that look great on backtest but they fail miserably when I test them live. Slippage is a bitch for shorter term trend following systems that need to get in the market fast without missing the trade. I have two systems that make money live and it was a lot of blood sweat and tears making them.
EDIT: I wouldn't sell them for under 1 million.
EDIT: I wouldn't sell them for under 1 million.