A new benchmark from AI-visibility platform CiteLens, based on 320 real buyer queries across ChatGPT, Perplexity, Claude and Google's AI Mode, found that the four leading AI answer engines disagree sharply on which brands they recommend. Google's AI Mode drew 93% of its citations from Google's top-10 organic results, and Perplexity 89%, meaning classic search engine optimization still decides who these engines cite. Claude pulled just 53% of its citations from Google's top-10, and ChatGPT only 30%. For ChatGPT, 70% of the sources it recommended ranked in neither Google's nor Bing's top-10. Statistical analysis revealed three distinct behaviors: search-ranking machines (Google AI Mode, Perplexity) with citation frequency correlated almost perfectly with Google ranking (0.92 and 0.87); the brand machine (Claude), where 58% of citations went to sites with a Wikipedia presence; and the black box (ChatGPT), which followed neither Google ranking nor brand popularity, with only 21% of citations going to Wikipedia-backed sites. Fewer than 4% of ChatGPT's citations appeared in Bing's top-10. Alper Tekin, Founder of CiteLens, stated: "SEO gets you into Google's AI and Perplexity, but it barely moves ChatGPT."