We all know that "if you build it they will come" works best in the movies. If you build a better mousetrap, you will have a better mousetrap. Possibly you will have lots of them if you have mass-produced in the conviction that a better mousetrap will be a big-seller.
In a world of limited resources, how do you know what needs to be better if you are to be more successful? The only presupposition that is useful here is the presupposition that you do know - you have had times when you have made improvements and been more successful as a result. You can go back to those situations and learn from them.
Let go of the answers you think you have. Commit to success. Be prepared to change your focus. Then go back to a time when making improvements allowed you to achieve what you wanted. Notice what was different then. Move your awareness from the product or idea, outwards in ripples. Notice your own state at the time, your market, your context. Notice your timing.
Learn what you need. Then make the right changes. So that better will mean success.