Final answer:
Paragraph 6 details the advantages of books to support the author's belief about their value.
Step-by-step explanation:
Paragraph 6 contributes to the author's message in the passage about the value of books and libraries by detailing the advantages of books to support their belief about their value. The passage mentions that books have been an important means of transmitting information since the days of Gutenberg's first printing press, but acknowledges that the publishing industry is changing to electronic 'e-books'. This suggests that while technology is advancing, the author still recognizes the value of books and the advantages they offer.