I love analogies. I just thought of another one to describe search features such as Yahoo’s Instant Search and Google’s Suggest.
I think of it as walking into a library, asking for information on X and the librarian handing you a book and saying, here you go. Sure, the book may be just what you want, on the other hand, it might only provide you a fraction of what you need. Aren’t you better off being directed to the section of the library that contains dozens of book about your topic, rather than just one?
Recommendations are nice, but they should never be allowed to substitute the full spectrum of sources available.