On day nine I scanned them with my cell phone and sent a text to the number that came up: "Your Ro-Bo's are stuck in a loop, either you get them to give me a decent tip or I'll call the Ro-Bo Rehab Squad -- and you know how anxious they are to get their hands on your new tech."
Day ten, Michael and Theo arrived, as usual, talked, as usual, placed their order, as usual, stayed thirty minutes as usual, and paid by card as usual. As they were leaving, Theo pointed to the table. On it was my tip, a one-ounce solid-gold coin. Now, that was a decent tip. Looking at them I said, "Tell George, he can continue his testing at my restaurant, and thanks for the tip. I look forward to both of you coming again tomorrow.