I've never understood tipping (I moved to US from Europe in 1991). To me transparency is what's lacking. Tips, gratuities, service charges, or however else it might be called these days should be a part of the total invoice/bill; then everyone would be happy (people like us wouldn't be bothered to think about tipping, and those who love it would be pleased to see that it's there, in their bill, as a line item, as port charge, tax, and/or whatever any other fee it might be like dozens of those fees attached to phone bills or air ticket's purchases).