eMarketer: Google's share of the US search ad market is expected to drop below 50% in 2025 for the first time in 10+ years, as Amazon, TikTok, and others rise
A flurry of new offerings for advertisers is hitting the market — Google's grip on the nearly $300 billion search advertising business is loosening.
Context & Ripple Effects
The forecast extends a long-running erosion in Google’s relative advertising weight: eMarketer had already projected its share of all US digital ad spend to decline in 2019, while Amazon’s increased. Earlier reporting also documented advertisers moving substantial search budgets from Google to Amazon, a shift that makes retail-media search a meaningful alternative rather than a niche add-on.
This is therefore a market-share inflection point, not necessarily a claim that Google’s search business is shrinking in absolute terms. It comes after Google’s 2020 US ad-revenue decline and amid advertisers navigating changes to Chrome’s third-party-cookie treatment, which has complicated measurement and targeting across the ad market.
First-order effects
- The forecast gives advertisers and agencies a clearer benchmark for reassessing search allocations among Google, Amazon, TikTok and other growing ad platforms.
- Google faces a more visible loss of relative market control in US search advertising, while Amazon and TikTok gain validation for their advertiser offerings.
Second-order effects
- Advertisers are likely to demand more comparable measurement, attribution and pricing across search and commerce-led ad inventories as budgets become less concentrated on Google.
- Google will have greater incentive to defend advertiser spend through product and performance improvements, while rivals can use growing share to attract more campaign budgets and sales resources.
Third-order effects
- If share losses persist, US search advertising could become structurally more fragmented, with product discovery and commercial intent distributed across retail and social platforms rather than concentrated in a single general-search channel.
- The durable competitive question shifts from who has the largest search audience to who can best convert intent into measurable outcomes—a route-share contest that may reshape ad-market bargaining power.
The trend: Search advertising is evolving from a Google-centered market into a multi-platform contest for commercial intent, measurement and advertiser budgets.