Don't worry about anything besides;

1. What problem you are solving

2. How well are you solving that problem

3. How many people have the same problem

4. If 2 is "Excellent" and 3 is either a lot of people, or a few very rich, build that business.

My last suggestion, is select problems that you want to fix for yourself. Rather than a list of business ideas, I keep a list of problems I want to solve.