It turns out that the old saying "There's no such thing as a free lunch" is completely untrue! If you and a friend come to the Metropolis and say you saw this page on the net, one of you gets lunch....Free!!
One of you has to fork over some $cash$ for your lunch! The other one (and yes, ONLY one) gets a free lunch of the same (or maybe less than the same) price as the one you just bought!
Here's the Corporate version of what we just said....
Upon the purchase of one lunch, the customer shall be granted, without withholding, one free meal of equal or lesser value than the aformentioned purchased lunch.