The document outlines 7 common mistakes that marketers make: 1) Focusing on customer "needs" rather than their "wants". 2) Being too in love with their product rather than understanding customers. 3) Viewing marketing as only science or art rather than both. 4) Trying to please everyone rather than focusing their message. 5) Forgetting that frequent repetition is needed due to how quickly people forget messages. 6) Believing their price is too high without proof. 7) Relying solely on economic arguments rather than other factors like ease of use. The document advocates understanding what customers want emotionally and focusing marketing messages accordingly.