During his retirement from filmmaking, Lewis wrote and published over twenty books during his long business career in advertising, including "The Businessman's Guide to Advertising and Sales Promotion" in 1974 and "How to Handle Your Own Public Relations" in 1977. A slow but steady stream of books followed, which seemed to turn into a torrent in the 1990s. Lewis settled in Fort Lauderdale, Florida and founded his own advertising company, Communicomp, a full-service direct marketing agency with clients throughout the world.