I was still thinking about your reply, and I do see your point. I do think companies can run themselves in a way where their book value soon becomes a meaningless figure. However, I also believe that book value has a place in measuring a company's returns relative to its employed equity. It's one of the most important questions in investing: how much money does it take to make more money? It would be generally more accurate, I think, if you were to use tangible equity instead of book so as to exclude intangibles, but the premise is still the same. I also think that companies with negative P/Bs generally carry a lot of debt, which I of course never like.