The Maze: US digital advertising looks like a sprawling menu, but three channels absorb about 80% of spending: search, retail media and social. Each has a different heavyweight: Google, Amazon and Meta. That makes concentration a buying problem before it becomes a market-share headline. Yet channel share and company share are different denominators. Confuse them and an allocation shortcut becomes a false statistic. The August 2026 forecast also hides most figures, so precision has to stop where the evidence stops.
Three channels do not equal three companies. The US spending breakdown separates search, retail media, social networks and other digital advertising. Width represents a channel's share of the total; the split inside it represents the leading company's share of that channel. Hanzlik's roughly 80% refers to the first three channels together, including their smaller competitors. It does not mean Google, Amazon and Meta receive 80% of every digital dollar. That distinction leaves room for rivals within the largest channels as well as opportunities outside them.
Google's 85% is a search figure. The visible split puts Google at 85% and other search providers at 15%. The definition excludes retail media and YouTube, while including AI search. This is a narrower advertising business than Google's full portfolio. Search offers access to expressed intent: people asking for something already have a reason to act. The operational implication is to understand which searches convert profitably, rather than treat a dominant provider's reach as proof that every extra dollar works. Market concentration describes supply; it does not measure an advertiser's incremental sales.
Amazon and Meta lead different buying environments. Amazon anchors retail media, advertising around shopping activity; Meta anchors social networks. Their exact shares and the channel dollar totals are redacted in the 2026 forecast. The visible proportions indicate leadership, but cannot support exact percentages or a precise combined company share. The channel definitions are deduplicated: retail media excludes social, and search excludes retail media. Those boundaries help avoid counting the same category twice. They also remind operators that a useful budget comparison needs a clear definition of what is being bought.
Revenue definitions make the neat comparison messier. Google's search figures are gross, before traffic acquisition costs and direct revenue-sharing payouts; the other company figures are net after those payouts. Meta includes Facebook, Instagram and Threads, and excludes WhatsApp. These are accounting choices, not minor footnotes. Gross and net revenues cannot be read as identical measures of what each platform retains. Nor does the forecast identify equal returns, equal audiences or interchangeable customer journeys. Moving money between these leaders is a commercial experiment, not a calculation solved by their market positions.
Why it matters: Ecommerce teams need two allocation decisions: which buying environments serve their customers, and which providers earn spend within each environment. Give challengers a specific test of profitable sales or useful new reach. Keep the large platforms accountable to the same test. Roughly 80% makes a strong description of the US channel mix; it makes a weak budget formula. A forecast with redacted inputs cannot tell a brand its optimal allocation, however tidy the three logos look.
