Storage Units: AI Market Discovery Index

Benchmark Summary

Extra Space Storage led the Storage Units AI Market Discovery Index in August 2026 with valid recommendation coverage of 25.5%, ahead of Public Storage at 21.2%. The month saw notable movement, with four tracked brands recording declines beyond normal variation.

CubeSmart recorded the largest coverage decline, falling to 16.3% in August 2026 from 22.1% in July 2026. Public Storage posted a similarly steep drop, falling to 21.2% in August 2026 from 26.9% in July 2026. StorageMart and SmartStop also declined significantly, each falling to 4.8% in August 2026 from 9.1% and 8.7%, respectively, in July 2026. No brand recorded a significant coverage increase this month.

The benchmark began with 800 prompt-surface observations in each month and produced 627 qualified observations in August 2026 after qualification.

Current Benchmark at a Glance

Qualified surface breadth counts the canonical AI surface families with at least one qualified observation: ChatGPT, Copilot, Gemini, Perplexity, AI Overviews, and AI Mode. All six families were represented in both months.

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. See the AI Market Discovery Methodology.

For the strategic interpretation of this benchmark, read CiteWorks Studio’s analysis of how AI search is recommending Storage Units.

Current Brand Standings

How to Read the Standings

• Presence rate: share of qualified observations in which the brand is mentioned in the AI response.
• Valid recommendation coverage: share of qualified observations in which the brand appears in a valid recommendation shortlist.
• Top-three rate: share of qualified observations in which the brand is recommended within the top three positions.
• Rank-one rate: share of qualified observations in which the brand is the first recommendation.
• Net sentiment: positive minus negative sentiment among mentions, scaled to a 0 to 1 range.

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

Recommendation Coverage Movement

Largest Decline: SmartStop

SmartStop's valid recommendation coverage fell to 4.8% in August 2026 from 8.7% in July 2026, beyond normal variation. Its presence rate also declined significantly, to 12.4% in August 2026 from 18.5% in July 2026. In the current standings, SmartStop records a 2.1% top-three rate, a 1.4% rank-one rate, and net sentiment of 0.5.

Extra Space Storage records 25.5% valid recommendation coverage, while SmartStop stands at 4.8%. That recommendation gap matters because SmartStop is appearing in valid recommendation shortlists much less often than the category leader within the Brand Recommendation situations measured by this benchmark. The current benchmark does not establish why SmartStop's recommendation coverage and presence both declined, leaving the mechanism behind the measured gap unresolved.

Highest-priority diagnostic: Which prompts, AI/search surfaces, recommendation placements, or evidence sources are associated with SmartStop appearing less often in valid recommendation shortlists than the category leader?

Largest Decline: CubeSmart

CubeSmart's valid recommendation coverage fell to 16.3% in August 2026 from 22.1% in July 2026, a decline beyond normal variation. The brand's presence rate rose to 66.3% in August 2026 from 63.7% in July 2026, meaning CubeSmart was mentioned more often even as its share of recommendation shortlists fell.

Largest Decline: Public Storage

Public Storage's valid recommendation coverage dropped to 21.2% in August 2026 from 26.9% in July 2026, also beyond normal variation. Its presence rate held steady at 92.0% in both months, so the decline was concentrated in how often the brand was recommended rather than how often it appeared.

Largest Decline: StorageMart

StorageMart's valid recommendation coverage fell to 4.8% in August 2026 from 9.1% in July 2026, beyond normal variation. Its presence rate declined to 12.9% in August 2026 from 17.5% in July 2026.

Category Leader: Extra Space Storage

Extra Space Storage remained the category leader in August 2026 with valid recommendation coverage of 25.5%, down from 28.2% in July 2026. The decline was within normal month-to-month variation, and the brand's presence rate remained effectively unchanged at 97.6% in August 2026 versus 97.3% in July 2026.

Stable Brands

U-Haul declined to 12.3% in August 2026 from 16.1% in July 2026, within normal variation. Simply Self Storage moved to 0.3% in August 2026 from 0.0% in July 2026, and **Prime Storage held at 0.0% in both months.

Recommendation Placement Snapshot

Coverage alone does not show how prominently a brand is recommended. Among the leading brands, Extra Space Storage stood apart on first-position placement in August 2026.

Extra Space Storage's rank-one rate of 11.6% in August 2026 was more than double Public Storage's 4.6%, showing that similar levels of coverage can still hide different first-position rates.

Buyer-Intent Distribution

All 584 qualified observations in July 2026 and all 627 qualified observations in August 2026 fell into the Brand Recommendation class.

The current public series measures Brand Recommendation discovery only and does not yet contain qualified observations in the Pricing & Value or Multi-Brand Comparison classes.

Historical Measurement Record

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.

Scope Boundaries

This public benchmark does not measure:

• Market share or attributable sales outcomes.
• Every possible AI response to a given query.
• Organic-search ranking positions.
• Social media mention volume.
• Private or sponsored AI channels.
• Causality from a metric movement alone. The benchmark records change; it does not establish why the change occurred.

About This Benchmark

The LLM Authority Index AI Market Discovery Index tracks how AI search and assistant surfaces recommend brands within a vertical, using qualified prompt-level observations across six canonical AI surface families. New measurements are added to the same evergreen report each month.

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

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