I try to pay with card as much as possible. All my cash goes to my bookie.
Actually, These opinions make me think I should tip more in cash. There may be a business owner out there that pays out tips once a week and charges them 3% for cc fees.
But i do not worry much about them not claiming tips on their taxes. They should so the more it is regulated the better. If everyone paid their fair share of taxes, it might be less of a burden on the chumps like me that pay taxes on my W-2 wages year in and year out.