There will always be competition nipping at your heels. The only way to stay ahead of them is continuously innovate and expand upon the space you own. As you can see above, he constantly expanded his ideas and brought them to fruition, adding value to his customers, raising the bar, and changing the category. Constantly innovating, improving your product is the ultimate way to create barriers to entry. The goal is to launch the next act of your progression before the competition can catch up to what you have already been doing.