People who are well educated or want to be. As well as those that want to learn more than just the bare minimum. While there is a great amount of information that can be had on the internet there are certain books that have this information gathered and put in a fairly concise format and are usually in far more depth. Also, in general you don't have to worry about some random jackass posting a web page and calling them self an expert while knowing little about the subject matter when using a book.
There still is plenty of room in this world for the web and books/journals and completely reputable sources. Also, I not saying that the internet isn't one just that it is also full of the opposite when this is
less common with published sources.
edit: Looks like mark has beat me too it glad to know I am not the only one who believes reading books is still useful, I may only be 21 but I was feeling a little dated from the "web has everything it is awesomerz" response