What you must do now is not just read these classics. No, you need to copy them word-for-word in your own handwriting. If you are really serious about becoming a master copywriter, you will do this over and over. The idea here is not for you to steal these promotions but rather, to be influenced by them. You want good writing to become one of your automatic skills and rewriting superb ads and sales letters in your very own hand is the best way in the world to do this.
reminds me of Scott Scheper writing word-for-word Niklas Luhmann's zettelkasten