A little OT, there are a few freebies forums out there and some people actually make money by posting to those forums.
A couple of years ago one of my clients who offers free samples had a barrage of free requests one day (250+). We tracked 240 of those back to a posting in a freebies forum. After reading the post from the original poster, we had to step in for the client and post a disclaimer.
The original poster claimed that they received their free product and that the promotion extended to everyone. Well, that was not true. The promotion applied to those with a business. Also, we checked the records and the person who posted the topic never did place a free samples order. They just read what was on the introduction page for the free samples. :(
Needless to say, there were 240 people who did not get free samples. You have no obligations when offering a free product, none whatsoever other than shipping it out the door based on the consumers request. Once it ships, your only obligation is really to follow up with the consumer. :)