I get asked this question all the time, and honestly, the answer is very simple.
Selling on Amazon FBA is a PROVEN FORMULA: if you follow it, if all the numbers make sense, if you put in the TIME and the EFFORT and if the numbers make sense, there is literally ABSOLUTELY NO WAY you can fail.
It's the same thing as going to the gym -- you know that if you go consistently for 6 months to 1 year, without skipping days and really putting in the time and the effort, you WILL SEE RESULTS. That is a law and there is absolutely nothing that can come in the way of that fact.
And in reality, that's exactly how selling on Amazon works -- it's a proven STEP-BY-STEP formula that if you MASTER IT, you will CHANGE YOUR LIFE.