Interestingly in United States cash is much preferable to cards or apps. There are two different prices for cash and cards for gas. Cash price being lower...

In terms of my competitive advantage, I think that's my wife. She helped me get a very difficult promotion to the architect, she helped me with a few hundred thousand dollars from her savings when I was short on the deal, she payed off our house that we live in by herself, she is running an impeccable household while starting a successful new business. And that is without mentioning all the other things she does...