This document discusses 13 steps for creating effective direct mail campaigns based on human behavior. It notes that $55.7 billion was spent on direct mail in 2010 and people are bombarded with over 5,000 marketing messages per day. Some of the 13 factors that influence purchase decisions discussed include that people respect authority figures, are naturally curious, make assumptions based on who mail is from, are drawn to certain words, may say "no" when interested to learn more, and are motivated by both rational and emotional reasons.