Suggestion: At risk of sounding like a forum police, I think it would be much easier if this thread only contained links to free samples.
While obviously a post saying that the link is no longer working is appropriate, "+1", "thank you", "I got one" and "my dog will love this" just clog up this thread.
When posting a new sample in this thread, the poster can just know in his head that: People appreciate it, are getting it, and are happy with their free sample.