Well, demo forex is good for practice and testing, editing and creating your personal trading strategies, nevertheless it also can bring harm to you. It's kinda tough to believe in this fact, however it's a real truth. The maind idea is that novices are getting used to trade on demo and they can't make themselves to start off real trading, because of a real fear of losing money. They got used that they don't lose money and just earn them, that's why their psychology tells them that it's the best option, but if they transfer to a real account, they start losing money. Hence, people should stay on demo no long than couple of months.