Scientific Advertising (Unabridged‪)‬

Scientific Advertising was written by Claude C. Hopkins in 1923 and has been cited by many advertising and marketing personalities (such as David Ogilvy, Gary Halbert, and Jay Abraham) as a "must-read" book.
Hopkins outlines an advertising approach based on testing and measuring. In this way losses from unsuccessful ads are kept to a safe level, while gains from profitable ads are multiplied. Or, as Hopkins wrote, the advertiser is "playing on the safe side of a hundred to one shot".