Our Promo Emails files is a collection of tested and proven advertising and sales letters. Storing a promo. Emails is a common practice used by advertising copywriters and creative directors as a reference to project ideas. Authors and publishers can benefit from creating a swipeable file with best-selling titles to give them ideas for their own titles. Publishers can create a file with dragged headlines in press releases. Copywriters also need to keep copies of the ads in the swipe file for future inspiration. Promo Emails files are also commonly used by web marketers who need to gather a lot of resources not only about products but also marketing methods and strategies.