"We do not always know what we want deep down." - Gladwell
Why is it the best quote? Because it's true! I can tell you that from conducting many formal and informal market research groups that consumers aren't a wealth of great ideas. However, this is not to say that such research is not useful. It's important to try new things. Experimentation breeds new products.
In his talk, Gladwell presses that diversity is important in product creation.
"...in embracing the diversity of human beings, we will find a sure way to true happiness." - Gladwell
Have a look for yourself. It's a fun watch :)