For me a book is very good if you want something to take you all the way through a subject. For this you accept whatever slant is applied to the material by the author.

This is fine but rarely (now I have a fair bit of experience) do I want to be taken all the way through a subject. I might be interested in a chapter or more likely a few pages of a book or a particular technique. Does this mean I have lost the focus required to go through a book on a whole subject? Well, no I hope, however it is just not relevant to my job where I know most of what I want to accomplish, but extend my reach a little bit. The bite size chunks of teh interwebz are sadly mostly exactly what I need.

In summary, books are just not relevant to what I need to do with databases.