DOES FREE REALLY HAVE ANY VALUE ?

Last year i put a sofa at the curb because i had no use for it anymore
The sign read "FREE"
It sat for 3 days......so decided to make a change
The new sign read "$ 10.00", the sofa was gone in 3 hours !
What does this mean?, the minute you put a price on something it has value ?, and then when it was free it had no value?.....Oh come on !
What has society become?.
In this instance alot can be chalked off to perception "Must be something wrong with it"....Who really knows, I am really at a lost for words on this one !