The article makes good points about how stories are the best way to hold people's attention. The beginning advice about not explaining the history is a little unclear. I think it would be better to say "stick to a central topic and don't go off on tangents, unless you are going to relate them back to the central topic." What if I am interested in the history of the washing machine or the chemistry of detergent? There isn't just one type of explanation. What's the difference between tutorial instructions and conceptual coverage?