What this means
Attribution, linking, and source selection in AI-generated answers.
Historical record
Perplexity introduces Q2D-Web for large-scale retrieval evaluation in agentic RAG
The visible user prompt is not necessarily the query a source competes for. AI visibility therefore depends on several distinct stages: query reformulation, first-stage retrieval, ranking, evidence selection, and eventual citation.
Google expands AI Mode and Deep Search using query fan-out
Topical completeness, subtopic relevance and retrieval across multiple intents become central to AI search visibility.
Anthropic launches web search on the Claude API
AI discoverability extends beyond consumer search interfaces into embedded enterprise and developer workflows.
OpenAI launches ChatGPT Search
ChatGPT became a direct discovery channel where crawlability, source selection and citation visibility matter.
Google launches AI Overviews broadly in U.S. Search
AI inclusion, source selection and click behavior became material concerns for mainstream SEO and GEO strategies.
Research paper formally introduces Generative Engine Optimization (GEO)
GEO became a named research problem with explicit visibility metrics rather than only an informal marketing practice.
ChatGPT web browsing begins rolling out in beta
Website discoverability became directly relevant to ChatGPT answers and later evolved into a dedicated search product.
Microsoft launches the new AI-powered Bing
Generative answers and citations moved into a major search engine, accelerating the need to understand visibility beyond traditional rankings.
Perplexity launches its answer engine
It helped establish the answer-engine model that later drove GEO, citation tracking and AI visibility measurement.
OpenAI WebGPT demonstrates browser-based answering with citations
The retrieve-read-cite pattern closely anticipates later AI answer engines and modern citation optimization concerns.
Retrieval-Augmented Generation (RAG) is formalized in research
RAG is one of the core technical patterns behind modern AI search, source retrieval and citation behavior.
Google introduces Featured Snippets
This is an important precursor to AEO: content structure and extractability became a visibility objective distinct from ordinary ranking.