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The most expensive AEO mistakes remove a site from the candidate pool before content quality matters: blocking the crawlers that feed AI answers, publishing pages that fall under Google's scaled content abuse policy [2], and leaving main content in client-side JavaScript that no major AI crawler executes [11]. Access rules are easy to get wrong because every platform separates its search crawler from its training crawler, so disallowing GPTBot only signals a training opt-out while disallowing OAI-SearchBot removes a site from ChatGPT search answers [7], and a CDN-level block on training crawlers can now catch Googlebot as well [9]. The second cluster of mistakes is measurement, since Search Console's generative AI report gives impressions with no clicks and no average position [5], and Google Analytics only recently began grouping AI assistant arrivals into their own channel while still excluding AI Overviews and AI Mode [6]. Judging the program by referral volume is the most common misread of all: AI-referred traffic sat at 0.2% of visits across 6,500 sites in Contentsquare's 2026 benchmark [14], while Ahrefs recorded 0.5% of its own traffic producing 12.1% of signups [13].