ADT is an American company that specializes in providing monitoring devices and services throughout the US. Its history goes back all the way to 1863, when Edward A. Calahan invented the stock ticker. By 1874, 57 district telegraph delivery companies had come together to form the American District Telegraph. Since then, ADT has ventured into various fields, including fire and security alarms. By 1964, it provided around 80% of US central station alarm services. Now, whether you want just basic protection or a full-fledged security system, keep reading for an ADT coupon and ADT promotions that will help you sweeten the deal!