i heard of the book "the long tail"

i heard about it in the darien librrary director's blog:

And last night, I heard Chris Anderson, author of The Long Tail, lecture at the New York Public Library. I also heard Chris speak at the American Library Association meeting in June, and I am certain that the long tail has implications for library services. I am just not sure what they are yet. Certainly we are going to be thinking more about niches in our collections and services. Are we buying what you want to read, listen to, and view?