I bought this book because it was advertized in The New Yorker and because I loved the title. Well, except for the title and the introduction, I found the book neither useful nor amusing. It is redundant and too long. The author thinks herself very witty and can't get enough of herself telling the same jokes. Why offend readers' intelligence by explaining the humor of the title? I agree with an earlier reviewer that some of the examples may be wrong, such as 'NO DOGS PLEASE'. As far as I know, it is incorrect to use plural after 'no' or 'any'.
The tone of the book is sometimes arrogant: we grammarians against the rest of illiterate world. After making an informal street survey and - perplexingly surprised - hearing people say they care about punctuation, the conclusion that seems most logical to the author is that ... respondents did not tell the truth!
Finally, I had thought that the 'free grammar repair kit' was a quick reference to punctuation (a one-page tear-out thing). But it was a collection of cut-outs of commas, periods, and other puncutation marks. How is one to use it? Doesn't it belong to the children's edition (but then the signs would need to be self-adhesive!).
This book is too long for what it wants to say. I will stick with my old friend "Elements of Style" by Strunk and White, which comes from a more authoritative source (if only for the US conventions), offers better practical advice, funnier humor, and skips the paranoia.