Pigeon eloquently pointed out in a previous post that there ain't such a thing as a free dinner. This being my third consecutive week with way too many work-related "free" lunches and dinners, I'd like to expand on this point.
First of all; this only applies to lunches and dinners in which there is an obligation involved outside the realms of friendship. Even though one might be a cantankerous bastard and make the point that dinner with friends still ain't free because you either go to a restaurant or it's expected that you in turn make dinner at a later occasion, what you gain is more than what you have to put in (unless your friends suck, in which case you have more problems than the pecuniary to worry about). These dinners and lunches take place in your free time, but you have them 'cause you choose to, not out of a sense of obligation.
Now; to the other "free" dinners. Just to be all pedantic guy on y'all, I'd like to summon my vast skills in statistics and remind you that all events reside in a probability space between the asymptotic values of 0 and 1. Thus, to paraphrase Captain Jack Sparrow, a free dinner is unlikely, rather than impossible. How unlikely, you ask.
Imagine the Abominable Snowman milking the Loch Ness Monster to get milk for his pet Unicorn. I reckon' I'll see this about five times while driving to work before I experience a free lunch or dinner.