I recently gave away an ugly backyard shed for free on CraigsList provided the person came to pick it up. Within minutes of posting the item I got 7 emails. I deleted the post immediately. I responded to the person who seemed best able to take it (she had a tiltable trailer with a winch on it) and set it up for Saturday. She failed to show saturday, so scheduled Monday. She failed to show Monday, but came Tuesday. I wasn't too worried about which day she came but did want it gone.
The 9.5 foot wide shed was at the end of a 20 foot long concrete pad that was 10 feet wide with a tree on one side and my garage on the other side. At the end of the pad was my alley. So she had to thread the shed down the pad between the tree and the garage without hitting anything, turn the corner at the end of the pad so it could be loaded onto her 20 foot long trailer. The winch on her trailer was broken. It took my battery charger, several screws and boards I had handy, and a few hours of my time to get the thing loaded on her trailer. Her truck hit my neighbor's fence and left tracks in the alley. I am not happy about that.
Structuring better "free" sales for Craigs List
If you are giving something away for "free" as long as they pick it up, I suggest you keep the listed price at zero and keep the title as "Free" but then in the details and in your communication with the person strike a slightly different deal: they pre-pay you $100 for the privilege of taking it for free which you decide whether to keep or give back. If their removal of the item meets your standards then you promise to give back the $100. If they ruin something or break something or - worst - abandon the pickup you keep the $100 to help pay for whatever the problem is.
My theory is that this will reduce the demand to only serious people who will show up on time, with the right tools/equipment to get the item.