Is AI citation a real ranking factor or a marketing buzzword?

Both. Multiple AI engines (Perplexity, Google AI Overviews, Bing Copilot) openly publish citation lists in their answer flows. Whether to call it 'ranking' is semantic - what matters is whether your URL appears as a cited source when someone asks an AI engine about your category.

Will Google penalise me for llms.txt?

No. llms.txt is invisible to Googlebot's organic crawl pathway. It exists alongside robots.txt, doesn't interfere with sitemap submission, and is treated as a hint by AI engines that look for it.

Do I need BreadcrumbList on my homepage?

No. The homepage is the root - there is no parent. BreadcrumbList only applies to sub-pages (/services, /blog/post-slug, etc.).

What's the difference between this and a normal SEO audit?

A normal SEO audit checks Googlebot's signals (canonical URLs, meta titles, sitemap, internal links). An AI-citation audit checks signals specific to ChatGPT, Claude, Perplexity, and Gemini citation pathways. Overlap is roughly 60%; the other 40% (llms.txt, AI-specific schemas, AI crawler access, passage citability) is what's new.

Should every page have all 9 signals?

No. Signals 1, 2, 5, 8 are site-level (robots.txt, llms.txt, semantic HTML, performance). Signals 3, 4, 6, 7, 9 are per-page and matter most on pages you actually want cited (homepage, key service pages, long-form articles, glossary entries).

How to audit a website for AI citation (2026 guide + free checklist)

The 9 signals AI engines look for when deciding which URLs to cite in their answers - AI crawler access, llms.txt, schema completeness, E-E-A-T, semantic HTML, passage citability, internal anchor text, page speed, outbound citations.