This kind of goal (N diners, N-1 plates) is so easily gamed, there's almost no point in setting it. The plates will just get a bit bigger and a bit more expens

This kind of goal (N diners, N-1 plates) is so easily gamed, there's almost no point in setting it. The plates will just get a bit bigger and a bit more expensive or they'll offer combo plates with two items. Much simpler is a scheme used by all you can eat sushi places (at least where I live). Eat up, or we'll charge you for the stuff you left uneaten (and no doggie bagging either).