Anyway you look at it, books -- and content for that matter -- have to be useful, practical and entertaining. And in no category does this apply more than with business books. While philosophy books can stray from the practical, business books are often measured by how applicable they are in everyday life. After all, textbooks are packed with theories, hence the necessity for practicality in business books.
http://www.askmen.com/money/professional_60/66_professional_life.html
