Do you have a great idea? ... Of course you do; you have at least three. In fact, you probably even have about five good ideas too. Maybe even another few mediocre ones you haven't bothered with. The difficult part of all your genius notions is that fundamentally their awesomeness doesn't matter. Your success will not necessarily depend on the perfection of the idea you choose to run with. What matters is all the work you put in, and of course-- luck.