It's not bad, but it's free on the web. And in terms of "getting real", they could stand to make a real book out of it by getting an ISBN number for it with all the money they made off of people throwing their money at them.

And of course I'll add the obligatory mention of Squeezed Books, which is more or less based on business books I've bought and enjoyed (although there are also others like Good to Great that I wouldn't recommend).