The Metro Detroit area includes at the very least Wayne County, Oakland County, and Macomb County; it serves as convenient shorthand for someone to say they are from one of the suburbs of Detroit but not to specify which one in the first conversation with someone who is not familiar with the area.

Metro Detroit is served by Detroit Metro Airport; if you take that perspective on geography, the effective metropolitan area of Detroit includes Ann Arbor and the rest of Washtenaw County.

The Metro Times alternative newspaper reaches readers in Ann Arbor and Ypsilanti, but those two cities are outliers to its distribution system which is primarily to Wayne, Oakland, and Macomb counties.

The Detroit DMA is used by marketing companies to describe a region which includes Lapeer, Livingston, Macomb, Monroe, Oakland, Sanilac, St. Clair, Washtenaw, and Wayne County.