Ben Horowitz wrote a pretty good preface to this one.
Over the years, I have come to consider High Output Management a true masterpiece, and there are at least three core aspects to its genius. First, in as little as one sentence, it lucidly explains concepts that require entire books from lesser writers. Second, it consistently uncovers brand-new management ideas or finds new insights in old standards. Finally, while most management books attempt to teach basic competency, High Output Management teaches the reader how to be great.