(Almost) all comments are useful

In the acknowledgments for his new book, Seth writes,

When I [Seth] was unsure about what to do--and this happened a lot--I would phone Marian [his book editor] and ask. I'm a little amazed how often I agreed with her suggestions.

Actually, I don't think he should be so amazed. I've found almost all comments to be helpful when writing books. Commenters have different perspectives than I do, they see things I miss, and of course I'm free to ignore the comments I disagree with. So I'm not surprised that I agree with most of their suggestions.

P.S. I don't always find anonymous referee reports from journals to be helpful, however. I think the main problem with referees is that they're too focused on acceptance/rejection rather than on improving the article. When I send someone the draft of my book, they know it's going to be published, and they know their comment has the opportunity to make a change in something that will actually be read by thousands of people. This is a good motivator for them to try to say something useful.