Madison Avenue likes to boast about its media-buying clout, but the reality is even the biggest media services organizations are also-rans to the long tail of smaller, regional, bundled, or in-house media buying organizations. That's the finding of a MediaPost analysis of year-end media billings estimates for the major U.S. media-buying organizations released today by Comvergence.

The analysis shows that Madison Avenue's "Big 3" -- Publicis Media, GroupM and Omnicom -- combined represent only 38.5% of U.S. media billings, while "all others" represent nearly two-thirds of U.S. media buys.

In fact, the Big 3's share of total U.S. media billings fell two percentage points from 40.5% in 2019.

And if you analyze the individual media agency groups within those holding company units, the top 5 represent less than a third of total U.S. media buys. And that's including giant independent Horizon Media's 5.8% share.