A Designated Market Area, or DMA, is a proprietary geographic region used for media measurement across the United States. This designation divides the country into distinct local markets, primarily to standardize how audience size and media consumption are quantified. Understanding these areas is a requirement for businesses and organizations that rely on advertising and marketing to reach specific regional audiences. The DMA system provides a common language for media buyers, advertisers, and broadcasters to analyze and compare market potential.
Defining the Designated Market Area
A DMA is a group of contiguous counties where the population receives the majority of its media signals from the same central source market. The definition is based on the viewing habits of residents, meaning the boundaries are drawn around where people tune in to local television and radio stations. This grouping creates a consistent geographic zone that reflects the actual reach of a media hub, which is typically a major city. The primary criterion for inclusion is the measured media consumption of the county’s households, not simply physical proximity or political boundaries.
Who Determines and Governs DMAs
The sole proprietor and creator of the Designated Market Area designation in the United States is Nielsen Media Research. Nielsen developed this standardized system to measure local television viewing and other media consumption across the nation. The term “DMA” is a registered trademark owned exclusively by The Nielsen Company (US), LLC, which controls the boundaries and data. This proprietary system ensures a consistent methodology for media measurement across all markets. Nielsen reviews and adjusts the DMA boundaries annually to account for shifts in population and changes in media viewing habits.
How DMAs Are Used in Business and Marketing
The practical application of DMAs is central to strategic planning for businesses that engage in local and regional advertising. Advertisers use the DMA framework to precisely define and execute targeted advertising campaigns, ensuring their messages reach the intended geographic audience. Media buyers rely on DMA data to allocate advertising budgets effectively, comparing the cost of ad placements against the measured audience reach and size of the market. For a business, the DMA provides a standardized metric for calculating market penetration and assessing the performance of a product or service within a defined region.
The framework also allows marketers to tailor creative content to align with the unique demographics and cultural preferences of a specific market. For example, an advertiser might run a sports-themed promotion within the Philadelphia DMA that would not be relevant in a different region. By understanding the size and profile of each market, businesses can make informed decisions about resource deployment, balancing high-cost campaigns in larger DMAs with more focused efforts in smaller markets.
Key Characteristics of DMA Groupings
The DMA system provides a comprehensive and exclusive division of the entire United States media landscape. Every county in the continental U.S., Hawaii, and parts of Alaska is assigned to exactly one DMA. This means the groupings are mutually exclusive and collectively exhaustive. This structure ensures that no geographic area is left unmeasured or double-counted.
Total Number of DMAs
The total number of Designated Market Areas across the United States is typically 210. This number remains relatively stable over time, though Nielsen reviews the boundaries annually to reflect changes in population distribution or media viewing patterns. The consistent number of markets provides a stable base for long-term media and marketing analysis.
Naming Conventions
DMAs are generally named after the principal city or metropolitan area that serves as the media hub for that region. This central city is the source from which the majority of the population in the surrounding counties receives its media signals. If a single media market serves multiple large, distinct metropolitan areas, the DMA may carry a composite name, such as the Albany-Schenectady-Troy, New York, DMA.
Variability in Size and Population
The markets exhibit extreme variability in both geographic size and population density. The largest DMAs, such as New York and Los Angeles, contain millions of television households and cover dense metropolitan areas. In contrast, the smallest DMAs, like Glendive, Montana, may encompass a vast geographic area but only contain a few thousand television homes. This wide range highlights the standardized nature of the DMA as a media-centric measurement tool.
Distinguishing DMAs from Other Market Definitions
Users often confuse DMAs with other geographical and statistical metrics, but their purpose is fundamentally different. Designated Market Areas are media-centric, defined exclusively by Nielsen based on local media consumption and viewing habits. This makes the DMA a specialized tool for advertising, media buying, and audience measurement.
Metropolitan Statistical Areas (MSAs) and Core Based Statistical Areas (CBSAs) are government-defined metrics created by the U.S. Office of Management and Budget (OMB) based on census data. These areas are population-centric, defined by high density and close economic and social ties, such as commuting patterns. While MSAs and CBSAs are used primarily for economic analysis and statistical reporting, they do not always align with DMA boundaries. This is because a DMA prioritizes the reach of a media signal over population or economic connectivity.