I see several option: 1) double check your idea. I have not come to any unique idea of my own that is not implemented yet or not in implementation stage. In so

I see several option: 1) double check your idea. I have not come to any unique idea of my own that is not implemented yet or not in implementation stage. In some cases implementations are really poor but still they exist. 2) You have some know-how what makes implementation of your idea successful. They can steal your idea but they will fail to implement it successfully (some comments in this discussion give example of this). Let's say your idea is really big and you implement it first. So what? If it is really good to be copied they will copy it faster than you will get your first paying customers.