Entity Concentration

Entity Concentration describes the accelerating dynamic where AI engines route a disproportionate share of citations and recommendations to a small cluster of dominant brands within each category. Unlike traditional search, where the first page held 10 organic results and the second page held 10 more, AI engines typically recommend 2-4 brands per query. The result is extreme concentration: the top 10 brands in a category now capture 59.5% of all AI citations, up from 30.9% just two months prior.

The Concentration Mechanics

AI engines select brands to cite based on entity authority, source corroboration, and citation momentum. Once a brand achieves sufficient density across authoritative sources, it becomes the statistically probable answer — and each new citation reinforces that probability. This creates a compounding flywheel that is structurally different from traditional search rankings, where algorithmic updates could redistribute visibility.

The Herfindahl-Hirschman Index (HHI) — the standard economic measure of market concentration — jumped 293% in AI citation distribution over the same period. By any regulatory standard, most AI search categories now qualify as highly concentrated markets. The brands inside the concentration threshold gain visibility at the expense of everyone outside it.

Why Concentration Accelerates

Three structural forces drive entity concentration in AI:

• Training data reinforcement — Brands frequently cited in training corpora become default recommendations, generating more citations in outputs that become future training data
• RAG source selection — Retrieval-augmented generation systems prioritize authoritative sources, which disproportionately cover established brands
• Citation momentum — AI engines treat existing citation frequency as a trust signal, amplifying brands that are already cited

This is fundamentally different from SEO concentration, where long-tail keywords created space for smaller players. In AI search, the long tail collapses. A buyer asking a niche question still gets recommendations drawn from the same concentrated pool of authoritative entities.

The Strategic Urgency

Entity concentration makes the citation window a time-critical strategic concern. Categories that have already consolidated are extraordinarily difficult to break into. Categories still forming represent the last opportunity to establish the earned authority and entity signals needed to be inside the concentration threshold rather than outside it.

For brands not yet in the top citation tier, the path forward runs through Machine Relations — building the density of independent, authoritative coverage that shifts an AI engine's probability calculations in your favor before the window closes.