> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getcited.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Source Affinity

> The observed preference of a specific AI platform for certain types or categories of sources.

**Source affinity** is the observed preference of a specific AI platform for certain types or categories of sources when generating answers. Each platform has different affinities: [Perplexity](/concepts/platforms/how-perplexity-ranks-sources) favors editorial publications and structured reference sites; [ChatGPT](/concepts/platforms/how-chatgpt-search-works) draws from a broader mix including forums and brand-owned content via Bing; [Gemini](/concepts/platforms/how-gemini-search-works) favors Google-indexed high-authority domains.

## Why it matters

Understanding source affinities helps brands prioritize where to invest in content and PR for each platform. If Perplexity consistently cites tier-1 editorial publications for your category but rarely cites brand-owned sites, the highest-leverage optimization for Perplexity visibility is earning editorial coverage — not improving your own blog. If ChatGPT draws from a broader source mix, investing in owned content may be more effective.

## How it applies in practice

Cited's [source preference hierarchy](/concepts/foundations/ai-citation-sources) documents the general pattern (editorial > reference > industry-specific > brand-owned > aggregators), but individual platform affinities vary from this general ranking. Cited's dashboard citation source data shows which specific publications each platform cites for a brand's category queries, enabling platform-specific PR targeting.

## Related concepts

* [What sources LLMs cite](/concepts/foundations/ai-citation-sources) — the general source preference hierarchy
* [Citation source](/glossary/citation-source) — the specific pages platforms cite
* [Editorial citation](/glossary/editorial-citation) — the most common citation type across platforms