There is a common believe that idea does not matter, execution is all which makes a difference. But the reality is that the idea does count for something.
The issue is that once you have your idea, you need to make sure that you solidify its birth, growth and maintain it. If your idea is to only make money, then your chances for success are quite slim, instead one should look at the market cap,one revenue stream, targeted customer, USP,and negatives. Try to keep idea simple and start with one product which can solve problem for you and masses. Dont forget to be passionate about the idea and share it with everyone,so that you can learn a lesson from them,and don’t worry about people stealing the idea.
One can refer to this infographic by Visual.ly to check feasibility and scope of the idea.