I get this crap all the time. Being I do tree removal, right after every windstorm I get emails or facebook messages saying things like "Scott, two HUGE pine trees blew over in my moms yard last night. If you come up, cut them up, take all the wood and the branches with you, we'll give you the wood for FREE!!"....
Usually, I'll say something like "I'll come up tomorrow and give her an estimate......I'll treat you right, being you are a personal friend..."
And they come back with "Oh, OK, thanks. I was hoping someone would want to do the job for free being it's prime firewood...."
I usually hear back from them within two or three weeks saying "hey, when can you come up and give me an estimate?"