Model coverage matters because buyers do not stick to one engine. A team that only tracks ChatGPT misses the picture on Perplexity-using technical buyers and Gemini-using Google-account-bound buyers. Profound leads on raw count of engines; SE Visible and Otterly.AI cover the most popular engines at lower price points.
AEO glossary
Model coverage
Model coverage is the count of AI engines an AEO tool monitors, at minimum ChatGPT, Perplexity, Gemini, and AI Overviews; ideally also Claude, Copilot, Grok, Meta AI, and DeepSeek.