Thoughts from librarians:

"How could it harm authors to make their works more visible? The claim that Google Books hurts authors or publishers because it deprives them of some theoretical market for making their books full-text indexed online or leasing the books so someone else can do it is, I believe, implausible."
– Walt Crawford, Senior Analyst, Integrated Information Services, Research Libraries Group, Inc.
Source

"A young women came into my office with a question -- she's taking a Natural Science course in Life Beyond Earth, and while she's found a couple of articles on her topic of space elevators, she still needs to find a book reference for her paper. We don't seem to have any books on space elevators -- what to do? Well, I immediately went into Google Books and searched on "space elevator." Lo and behold, we immediately found a few books which seemed to have significant sections on space elevators. Checking our catalogue, we figured out which ones are in our collection. The student went away very happy. Not only is Google Books good for reference, I also immediately ordered a bunch of the books that we discovered that aren't in our collection."
– John Dupuis, Science Librarian, York University
Source

"Faculty like [Google Books], both as a research tool and as a tool that helps them make their cases for tenure – they can now find out about books that cite their work. I am also using Google Books as a tool to help me decide how to spend that part of my book budget that is discretionary. If a book cites another book that I already know is good, if it cites a faculty author, if it has information on a certain narrow topic of interest to a particular faculty member, I can now go out of my way to buy that book."
– Rachel Brekhus, Librarian, University of Missouri - Columbia
Source

"For the third time in the past week, I've been able to answer thorny reference questions using Google Books that I otherwise would have simply given up on. I tried Google Books and lo and behold – there was my mystery reference. That was more than enough to steer me to the proper volume on the shelves here at the library. Mission accomplished! Google Books and similar endeavors have given me a burst of optimism. Not only will scholarship be enhanced as a result of digitization, but it will become more relevant as well. The more that is scanned and made searchable, the more humanity as a whole will benefit."
– Tom Bruno, Library Assistant, Harvard University
Source

"[Google Books] has the potential to revolutionize research and to make the libraries of the world into the world's library."
– John Berry III, Editor-in-Chief, Library Journal
Source

"Earlier this week our new Teen Services librarian came in with this story: She was helping a fifth-grader try to find a book for a report. She had looked in all the sections she thought were applicable in the shelves and found nothing. So she tried Google Books. In the end, they found a book in a section they would never otherwise have thought to look. Child: happy, staff: happy, homework: saved."
– Jaemi Kehoe, Librarian, Goshen Public Library, New York
(From an email)

"I admire a company that is so in line with the premise of library ideals. The dissemination of knowledge, especially the scanning in of the university collections and making them available to all in the WORLD, is truly noble. You are not just working at a job. You will enable, in a strange way, the remaining doors of ignorance to be blasted away. You will allow those people who are still isolated from the rest of the world to experience the light of knowledge. Remain true to your vision. Go home at the end of the day with a sigh of well-earned satisfaction. Some people talk about changing the world. You are actually doing it."
– Laura Moody, Librarian, Gulf Shores Public Library, Alabama
(From an email)

"For the Bodleian Library, the 'liberation', from the depths of its vast stacks, of millions of its relatively obscure and out-of-copyright books (from all parts of the world, and in many languages), into the global accessibility of the Internet, is one of many ways in which the Library sees itself contributing to a better world for all. Public domain books belong where the worldwide public can use them; and that is where the Bodleian, like its other library partners, wants them to be seen."
– Reg Carr, Bodleian's Librarian at Oxford University, on Oxford's participation in Google Books