Gladwell opened by mentioning that three people came to his very first book signing, and was pleasantly surprised to see such a large crowd awaiting his arrival. I was roped off and segregated with a crowd of people who didn't have a book to be signed behind a larger crowd of people who had hardcovers. (One consequence of the proliferation of ebooks is that a number of them can be downloaded for free. For example, the torrent for the ebook and audio book for David and Goliath is on the Internet.)
After giving the example of the Viet Cong, Gladwell summarized David and Goliath by saying that what is in one's heart is the most important element in winning a battle or overcoming an obstacle i.e., a Goliath.
Lastly, Gladwell said that a representative from the toothpaste division of Procter & Gamble shared with him that despite the fact that Arm & Hammer's toothpaste is inferior to Procter & Gamble's Crest, people purchase Arm & Hammer's toothpaste because they associate baking soda with a clean kitchen and cleanliness in general. Gladwell went on to say that that false association may be the topic of his next book.