AI 引擎回答 120 個 B2B 買家問題時，第三方網站比官方網站更常獲引用

When someone asks ChatGPT or Perplexity "what's the best X for Y", the engine reads a handful of web sources, then writes an answer naming 3–5 brands. We wanted to know: which sources actually get read?

So we logged them. 120 B2B buyer questions, 5 engines (ChatGPT, Perplexity, Gemini, Claude, Google AI Overviews), every cited URL recorded and tallied by host. Three findings surprised us.

Official vendor sites lose to third-party pages — in every category In every single category we measured, vendors' own websites were out-cited by third-party pages: comparison articles, review sites, community threads, directories. The page a brand polishes hardest is the page AI reads least. Wikipedia alone was cited 36 times across the 120 answers.

If your AEO plan is "optimize our own site," you're optimizing the minority channel.

Single runs lie — ~15% of answers flip on re-ask Ask the same engine the same question twice and roughly 15% of verdicts change (Gemini is the flippiest). Any measurement based on one-shot snapshots is partly noise. We run every question × engine 3 times and score the consensus; the swing tightens from ±12.5 pts to about ±7.

If you've ever screenshotted "ChatGPT recommends us!" — run it twice more before you celebrate.

A technical gotcha: Gemini doesn't cite real URLs If you're building anything on Gemini's grounding metadata: the cited URLs are all vertexaisearch.cloud.google.com/grounding-api-redirect/... — opaque redirects, not sources. We dropped them as noise for weeks, which silently blinded one engine column of our citation data.

The fix is simple: fetch each redirect with redirect: 'manual' and read the Location header. No body download, one round-trip, real source URLs. (If you're on Vercel, do it server-side with a timeout — some of them hang.)

The practical takeaway: find your citation gaps
A citation gap is a source your category's AI answers repeatedly cite — but that never mentions you. Since the engine already trusts that source, getting genuinely listed there is usually the fastest route into AI answers. The DIY version:

Ask 6–10 real buyer questions on Perplexity and Google AI Overviews (they cite most consistently)
Record every cited URL, tally by host
Cross out hosts that already name you
What's left, ranked by count, is your to-do list
No engine sells positions inside organic answers. Anyone guaranteeing an AI ranking is guessing with your budget.