"Winners never quit" is stupid. Winners quit all the time: they quit things that aren't working out to seek better opportunities. This advice can be phrased better as "Never quit something with great long-term potential just because you can't deal with the stress of the moment."

Godin defines The Dip as that rough (and sometimes quite lengthy) period between the initial euphoria and excitement of a new endeavor, and the long-term success. In a marathon (a 26 mile run) the dip is between miles 10 and 23; you're exhausted but the end isn't in site yet. In a business, at least in my experience, this time is typically between from about 18 months in till about the three of four year point, which is generally about the earliest any product is likely to start to gain serious traction in a marketplace.

The book is short (always a plus) but I was a little disappointed by the disjointed writing and sometimes seemingly contradictory advice. It tantalized with advice on how to recognize a Dip as compared with a Cul-De-Sac (an opportunity that will never go anywhere), but then didn't expand on this much.

Still, the central thesis is dead on target. Everything we do in life - career, business ventures, relationships, hobbies, friendships - should constantly be re-evaluated, and if they are no longer providing substantial benefit or satisfaction, move on to something new. I proudly proclaim myself as a lifelong quitter.