Very few agencies specialize specifically in ChatGPT citation, because ChatGPT is the hardest engine to break into — look for agencies whose case studies name ChatGPT specifically, not just "AI search."
[01]/ the data
What we found
Only 4 of 82 companies we track were ever cited by ChatGPT, so genuine ChatGPT-specific case studies are rare and worth verifying directly.
[02]/ how to do it
Three steps
Ask for ChatGPT-specific (not general AI) before/after citation proof.
Be skeptical of vague "AI visibility" claims without engine breakdowns.
Start with Perplexity as the realistic entry engine while building toward ChatGPT.