Short bursts of information spaced between and within programs on radio and television earned the nickname spots. Spots include three specific type of announcements: public service announcements (PSAs), program promotional announcements (promos), and sales advertising (i.e., commercials, or commls). Each type fills a specific purpose in broadcast communication, but all have in common the required task of selling an item, a business, a concept, a philosophy, or a need to be filled in some way through an interchange of money, time, or effort.