I just literally said there was free stuff (there was, even a wooden sword with Knockback 1), and 10 people run towards the chest like it was the Cornucopia from The Hunger Games. Holy crap. I knew I needed to get rid of some junk but man people want it.
As long as you're actually giving stuff away, I don't see an issue with this. Also don't be dishonest, such as saying, "Free diamonds here!" when you only have dirt, etc. I would see that as a reason for at least a temp ban.
I voted yes because well they are free items. If I had another choice, I would say no as well because maybe someone can't get into the chest because everybody is crowding around it. I would do a free items shooter or a free items drop. EDIT: You can always do this (player's name)(the amount you want to give/sell)FREE(item)