Here is a fascinating letter from Hugh Hefner written in 1955. He seems to be responding to someone who purchased/wanted to buy a used copy of the first Playboy magazine. Not only does he give the reader a surprise gift (always a good way to create positive engagement) but he then encourages him to become a brand evangelist and spread the word (and a few gift subscriptions along the way). And you thought Word of Mouth marketing was a new concept.
<via Letters of Note>