Uhhh.. > > says "latte 4.50" > > pay 6.50 > You're never required to tip so the "advertised price" and the price at the register are identical. You choosing

Uhhh.. > > says "latte 4.50" > > pay 6.50 > You're never required to tip so the "advertised price" and the price at the register are identical. You choosing to leave $2 on top of that doesn't change anything, even if it's only done through social pressure. Taxes and tips aren't the same thing. Their $2 example is something you are required to pay.