Definition of market-by-market buy

method of purchasing commercial time on broadcast stations, where the time is bought in one market (geographical area) at a time, as opposed to a network buy, where the time is bought all at once on all the stations affiliated with the network throughout the region or country. Although a market-by-market buy is more time-consuming, advertisers will purchase commercial time on this basis when they want to direct the advertising only to specific markets. Also, a judicious media buyer can often make a more economical purchase of time in a market-by-market buy.