Ok, so I’m currently solving your math guide and while I think it IS great, I have also noticed that a large portion of it is directly copied off your blog posts. Even many of the questions in the book are directly taken from the blog. This was a little disappointing. 😔
First, thanks for buying the book. Your support makes it possible for me to provide free services (like this Q&A). Hopefully you’re finding that the questions that are exclusive to the book (and the other content that’s not on the blog, like the Blue Book Breakdowns, and the stuff only book owners have access to on this site) are making it worth your while.
One of the biggest challenges to a question writer is making sure that questions are worded unambiguously and aren’t too easy or too hard. Even College Board runs questions through experimental sections before they make it onto real tests to make sure they’re good questions; I use the blog for this purpose. In fact, I believe that one of the main reasons the Math Guide has worked for so many folks is that much of the content had been tested out on the blog (and in private tutoring sessions) before it made its way into the book. There are a lot of questions that didn’t make it into the book (or received major edits before they went into the book) based on blog reader feedback. The same, of course, goes for much of the non-question content. Early blog readers asked a lot of questions, which really helped me hone my explanations to make them as clear as possible.