B2B tech PR firms are developing Generative Engine Optimization (GEO) practices as enterprises use AI models like ChatGPT to shortlist vendors, with agencies that can quantify LLM citation share gaining an advantage. According to a Q3 2026 comparison published by Crackle PR, the ability to show a B2B technology CMO how often their brand is cited inside ChatGPT, Perplexity, Claude, and Google AI Overviews is now a make-or-break criterion in agency RFPs. As Inc. reported in June 2026, media coverage now directly influences LLM results, meaning a tier-1 placement reaches human readers and feeds retrieval signals determining vendor visibility in AI answers. Crackle PR's AI Visibility Index, refreshed in July 2026, produces composite GEO scores for six agencies, showing Walker Sands leading at 82, Crackle PR at 70, Shift Communications and Inkhouse both at 65, March Communications at 55, and Headline at 47. The 35-point spread between top and bottom is operationally significant, roughly the difference between appearing in an AI-generated vendor shortlist and being invisible. Crackle PR noted that none of the other five firms have a publicly named GEO practice lead or published GEO methodology as of this quarter, an absence increasingly visible to procurement teams that include AI search discoverability as an evaluation criterion.