If ChatGPT doesn't mention your brand, are you still relevant? That is the question increasingly worrying marketeers as consumers swap Google searches for AI-generated answers. The shift is giving rise to a new discipline — Generative Engine Optimisation (GEO) — as brands look beyond ranking on Google's blue links and instead compete to be recommended by ChatGPT, Gemini, Claude, Perplexity and Google's AI Overviews. Early adopters say the strategy is already paying off.