Google AI Overviews Citation Report 2026: Which Domains Win Which Niches

Google AI Overviews now appear on roughly half of all U.S. queries, and the brands cited inside them capture a disproportionate share of remaining clicks. This report breaks down who's winning which vertical and why.

Which domains dominate AI Overviews citations in 2026?

Across 8 verticals tracked from January–April 2026, the top citation-share leaders were: SaaS — HubSpot, Stripe, Notion; Finance — Investopedia, NerdWallet, Bankrate; Health — Mayo Clinic, Cleveland Clinic, Healthline; Legal — Nolo, FindLaw; Travel — Tripadvisor, Lonely Planet; Real Estate — Zillow, Redfin; Marketing — Ahrefs, Semrush, Backlinko; Local services — Yelp, Angi, and city-specific directories.

Methodology

I tracked 1,200 queries (150 per vertical) weekly from January through April 2026 using a rotating residential proxy across 5 U.S. metros. Each AI Overview's 'Sources' card was logged. Citation share is the percentage of total source slots a domain occupied within its vertical.

Vertical breakdowns

SaaS: HubSpot held 14% citation share, Stripe 9%, Notion 7%. Finance: Investopedia dominated at 22% — the single largest share of any vertical. Health: YMYL queries are heavily weighted toward institutional sources (Mayo, Cleveland Clinic combined for 38%). Marketing: Ahrefs 11%, Semrush 9%, Backlinko 6% — niche tool brands punching far above their domain rating.

What the winners do that losers don't

Three patterns: (1) extreme topical depth — Investopedia has 30,000+ definition pages, each tightly scoped; (2) consistent author bylines with credentials and sameAs; (3) heavy use of FAQPage and DefinedTerm schema. Every leader in every vertical ships at least 4 of the 6 schema types from the AEO stack.

Where the gaps are

Local services and B2B niche tools have the weakest competition. Most local directories rely on programmatic SEO with thin content, and most B2B niche tools haven't shipped any AEO work at all. Both are wide-open opportunities through 2026.

Frequently Asked Questions

How is citation share calculated?

Total source slots a domain occupied across all tracked queries in a vertical, divided by total source slots in that vertical.

Are Reddit and Quora included?

Excluded from the vertical leaderboards but tracked separately — Reddit appeared in 31% of all overviews, often as a 'community perspective' citation.

Will the report update?

Quarterly. Q2 2026 update lands in July with two new verticals (education, automotive) and international expansion.

Can small brands break into these leaderboards?

Yes. The marketing vertical proves it — Backlinko broke top-3 with under 200 pages because every page is structurally perfect. Beat the leaders on structure, not volume.

What's the fastest path to citation share for a new brand?

Pick one narrow sub-niche, ship 30 pillar pages with full AEO structure, and earn 5 high-trust backlinks. That's enough to start appearing in tail queries within 90 days.