A methodology for mapping devices to audience segments that relies on consumer panels assembled by Nielsen, Comscore and other data providers; it can say that the audience viewing your ad is probably heavily comprised of working mothers in their forties living in the Midwest, for example. This is still how most TV is measured. Statistical modeling and predictive algorithms, which are populated via device fingerprinting, IP matching, operating systems, locations and other data points, may also be leveraged.
