First Citation

Publications

Research & Reports

Data-driven research on AI citation behavior, generative engine optimization, and the emerging science of LLM recommendations. All findings are peer-reviewed and backed by reproducible methodology.

March 2026

The First Citation Index: Q1 2026 Report

A comprehensive analysis of AI citation patterns across 14 industries, measuring how ChatGPT, Perplexity, Gemini, and Claude recommend brands and resources. Includes quarter-over-quarter trend analysis and predictive modeling for citation trajectory.

Citation Index
Quarterly Report
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February 2026

How LLMs Decide What to Cite: A Technical Analysis

Reverse-engineering the citation decision framework used by large language models when generating recommendations. We identify six primary factors that determine whether a brand is cited, ranked by influence weight.

LLM Behavior
Technical
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January 2026

GEO vs SEO: The Definitive Data-Driven Comparison

Based on 500+ controlled experiments across four major AI models, we quantify the divergence between traditional search engine optimization and generative engine optimization. Results show a 73% correlation decay between Google ranking and AI citation probability.

GEO
SEO
Comparative Study
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December 2025

The Authority Signal: What Makes AI Trust a Source

An empirical study of 12,000 AI-generated responses to identify the content attributes most strongly correlated with citation. Structured data, domain authority, and recency each contribute differently depending on query intent category.

Authority
Content Strategy
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November 2025

Brand Visibility in AI-Powered Search: A Cross-Model Study

We tested 1,200 branded queries across ChatGPT, Perplexity, Gemini, and Claude to measure citation consistency. Only 11% of brands were cited by all four models, revealing significant model-specific biases in recommendation behavior.

Brand Visibility
Cross-Model
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October 2025

Citation Decay Rates in Large Language Models

Longitudinal tracking of citation patterns over 90-day windows reveals that AI citation is not static. Brands experience measurable decay in citation frequency when content freshness signals diminish, with an average half-life of 47 days.

Citation Decay
Longitudinal
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September 2025

The Role of Structured Data in Generative Engine Optimization

Schema markup, knowledge graphs, and structured content formats are tested for their impact on AI citation probability. JSON-LD implementation increased citation rates by 28% compared to unstructured equivalents across 800 test queries.

Structured Data
GEO
Technical
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August 2025

Industry Report: AI Citations in SaaS and Technology

The technology sector leads all industries in AI citation rates at 34%, but distribution is highly concentrated. The top 8% of SaaS brands capture 61% of all AI-generated recommendations in their respective categories.

Industry Report
SaaS
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