Recruiting Agencies: AI Market Discovery Index

Benchmark Summary

Robert Half led the Recruiting Agencies category in September 2026 with 46.7% valid recommendation coverage, holding a 7.6-point lead over second-place Randstad at 39.1%. Adecco followed at 33.9%. Robert Half's leadership position is unchanged from the July 2026 baseline, when it also led the category at 46.8%.

Comparing September 2026 against the July 2026 baseline — the last month with comparable brand-level signal before an August 2026 measurement gap — no tracked brand recorded a significant increase in valid recommendation coverage. Randstad posted the largest baseline-to-current gain of any brand, edging up from 38.2% to 39.1%, a difference within normal month-to-month variation. Two brands recorded significant declines: Spencer Stuart, which fell from 21.5% to 14.4% (down 7.1 points), and Heidrick & Struggles, which fell from 19.8% to 14.8% (down 5.0 points). The remaining eight tracked brands, including category leader Robert Half, are classified as stable relative to the July 2026 baseline.

August 2026 recorded no valid-recommendation signal for any tracked brand, an instrument-level gap rather than a business decline. The September 2026 comparisons in this report are made against the July 2026 baseline rather than the intervening August month.

Current Benchmark at a Glance

Qualified surface breadth counts the canonical AI surface families (ChatGPT, Copilot, Gemini, Perplexity, AI Overviews, and AI Mode) with at least one qualified observation. All six families were present in each month of the series. August 2026 represented an instrument-level interruption in the series, with no brand signals recorded; September 2026 restored the pattern seen in July 2026.

For the strategic interpretation of this benchmark, read CiteWorks Studio's analysis of How AI Search Is Recommending Recruiting Agencies

Research Scope and Qualification

The public benchmark is narrower than the raw collection universe by design. Brand-level percentages use the qualified observations as the public denominator, not the raw collection size.

For full methodology, see AI Market Discovery Methodology.

Current Brand Standings

Robert Half held the strongest position in September 2026 with 46.7% valid recommendation coverage, followed by Randstad at 39.1%. The table below is sorted by valid recommendation coverage.

How to Read the Standings

• Presence rate: share of qualified observations in which the brand is mentioned at all.
• Valid recommendation coverage: share of qualified observations in which the brand receives a valid recommendation.
• Top-three rate: share of qualified observations in which the brand appears in the top three recommended positions.
• Rank-one rate: share of qualified observations in which the brand is the first recommendation.
• Net sentiment: positive minus negative sentiment among mentions, on a scale from -1 to 1.

For formulas and denominator rules, see AI Market Discovery Metric Definitions.

Recommendation Coverage Movement

Across the current benchmark cycle, most brands sit at levels close to their July 2026 baselines, and no brand shows a significant increase in valid recommendation coverage from baseline to current. Two brands, Heidrick & Struggles and Spencer Stuart, recorded significant declines. The remaining eight tracked brands, including category leader Robert Half, are classified as stable within normal month-to-month variation. Robert Half's presence rate moved from 70.6% in July 2026 to 64.0% in September 2026, while its valid recommendation coverage held near baseline at 46.7%.

Largest Decline: Spencer Stuart

Spencer Stuart's valid recommendation coverage fell from 21.5% in July 2026 to 14.4% in September 2026, a decline of 7.1 points, the largest of any tracked brand. The brand's presence rate declined from 32.1% to 28.7% over the same period, while its rank-one rate rose slightly from 0.2% to 1.6%.

Additional Decline: Heidrick & Struggles

Heidrick & Struggles' valid recommendation coverage declined from 19.8% in July 2026 to 14.8% in September 2026, a drop of 5.0 points. The brand's top-three rate also declined from 8.5% to 7.6% over the same window.

Category Leader: Robert Half

Robert Half led the category with 46.7% valid recommendation coverage in September 2026, holding a 7.6-point lead over Randstad. The brand also led on presence rate, top-three rate, and rank-one rate, including a 22.9% rank-one rate that shows strong first-choice strength.

Recommendation Placement Snapshot

Coverage alone does not show how prominently a brand is recommended. Robert Half and Randstad, the two brands with the highest coverage in September 2026, illustrate how placement can differ.

Both leading brands posted higher rank-one rates in September 2026 than in July 2026: Robert Half moved from 22.1% to 22.9% (up 0.8 points) and Randstad moved from 5.4% to 7.6% (up 2.2 points). Close overall coverage can still hide very different first-position rates: Randstad's 7.6% rank-one rate trails Robert Half's 22.9% by roughly threefold.

Buyer-Intent Distribution

All qualified observations in September 2026 fell into the Brand Recommendation class.

The current public series measures Brand Recommendation discovery exclusively and does not yet address pricing, value, or head-to-head comparison questions.

Historical Measurement Record

This is an evergreen benchmark URL. New measurements are added to the same report.

Evidence and Source Layer

The benchmark is built from prompt-level observations that retain the query, AI/search surface, answer, brand outcome, recommendation placement, sentiment, and, where exposed, citations or attributable evidence sources. Source presence is evidence about the information environment. It is not automatically proof that the source caused the recommendation.

September 2026 returned the category to a state consistent with July 2026, after August 2026 recorded no brand-level signals for any tracked brand. The benchmark documents this pattern but does not establish why the August interruption occurred.

Scope Boundaries

This public benchmark does not measure:

• Market share or sales attributable to AI-driven discovery
• Every possible AI response, only the sampled prompt-surface combinations
• Organic-search ranking or social mention volume
• Private or sponsored channels
• Causality from a metric movement alone

The August 2026 gap and the absence of pricing and comparison data mean this benchmark should be read as a directional signal, not a complete market picture.

About This Benchmark

The LLM Authority Index AI Market Discovery Index tracks how often brands are present and recommended across leading AI search and assistant surfaces. Each month, the benchmark publishes category-level standings based on qualified prompt-surface observations.

• AI Market Discovery Methodology
• AI Market Discovery Metric Definitions
• AI Market Discovery Research Standards
• Modeled AI Authority Value

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