Important to know about free food: you shouldn't just accept all of it without regard to propriety and without regard to the quality of the food.
For an example, let's look at my behavior at shrimp tasting last week. I walked into the lab, selected my two cupsful of shrimp and ate them. You don't HAVE to eat the shrimp to taste them. We have chew 'n' spit going on in the tasting lab, especially when there are spawny oysters. But I always eat the proteinaceous free food unless it is clearly septic.
When I was finished with the taste test, I went over and punched the clock. (We don't actually have a clock, but I like to imagine we do--I'd like it to be like the clock in the Warner Bros. cartoon with Ralph and Sam, the coyote and the sheepdog). Near the clock, I noticed a bowlful of crappy supermarket chocolate. Because two of my fellow shrimptasters were having a spirited discussion about one of their co-workers and how she is an idiot and has an idiot boyfriend and how this idiot and her boyfriend, in cahoots with an idiot boss, have managed to fry three+ motherboards in the past year; because, I say, because of this spirited conversation, I was unable to simply walk out of the shrimptasting lab. Instead, I leaned against the wall next to the time clock and ate a wad of crappy supermarket chocolate about the size of a ground squirrel.
Shrimp: Good Free Food
Crappy Melamine Chocolate: BAD Free Food.
Eat Good Free Food
Don't Eat Bad Free Food.