Here's the scenario: You've all enjoyed a wonderful meal and nobody's in the mood to tally up. Suddenly, one of your group volunteers to put it all on plastic. Relieved, you throw cash at the benevolent problem solver, who halfheartedly tosses back change and usually walks away with at least their tip taken care of, if not half of their meal. Most of us are willing to pay a little extra for the relief of not having to ruin a perfect meal with mundane accounting and the card shark knows it.