This book does have a very useful list of headlines, opening sentences, and a knowledgeable section on envelope copy with illustrations...
..but the guy explains these things in such a bizarre vernacular and egotistical vibe that it was hard for me to feel any sort of enthusiasm as I was learning (or trying to). Maybe Lewis should've been a politician.
If you want a sales letter book, I fully recommend Dan Kennedy's 'The Ultimate Sales Letter'. It's step by step, easily understandable, fun to read and teaches you everything Lewis does but much more. Your excitement will skyrocket. Kennedy's your Man.
The latter half of the book are "100 ways to start a sales letter". It ought to be a gold mine. It IS of value, but on nearly all of the illustrated "ways", Lewis illustrates how people foul them up; not in how they are used successfully.
The same is true for the first part of the book. He helpfully offers actual samples of sales letters that he has received but spends most of his time mocking them and showing what's wrong. Certainly many of them deserve criticism but I wonder how much better the book would have been if Lewis had given examples of GOOD copy.
I recommend the book. I was just disappointed that it continually focused on the negative instead of helping the reader with GOOD copy.