Rich Cohen, an award winning non-fiction writer, shared the following in a Vanity Fair article about his effort to ghostwrite a book for Theodore Forstmann. "Writing a nonfiction story is like cracking a safe. It seems impossible at the beginning, but once you're in, you're in."
And that is exactly what I experienced while writing the 2nd edition of The Allure of Nymphets. The 1st edition is approximately 180 pages, in size 10 font and 1.5 spaced. (The choices were partially made as a marketing strategy for the paperback edition.). The 2nd edition is approaching 400 pages due to a deluge of very relevant and engaging information.
Thus, I would concur with Cohen. As a nonfiction writer you shouldn't hesitate to write a book based on a fear that you will not have enough information, because you'll probably have too much information to choose from once you crack the safe.