JB Hi-Fi appeared in 21 of 40 ChatGPT answers in our Black Friday test. It was the recommended store in 2.
Officeworks appeared in 13 and was recommended in 7.
Only the recommendation sends the shopper to your site. Track named rate and recommended rate as two numbers.
The four measures we’d track before Black Friday: coredna.com/blogs/chatgpt-bl…
Margaret Mitchell of Hugging Face, opening RecSys 2026: “an approving click doesn’t necessarily indicate the best action.”
Tired reviewers approve fluent plans, so agents learn to produce what is easy to approve.
Her test: plant a known error and see if it gets caught.
Her full argument, and how to measure AI properly: coredna.com/blogs/recommenda…
Our CTO gave Claude one brief: live reporting for a client’s sign-up forms, some with more than 300,000 submissions.
Claude wrote a plan. Dmitry reviewed it. Then Claude built a new content type, a 13-step automation and a 26-step automation on a dev copy of the site.
How the build worked, step by step: coredna.com/blogs/whats-new-…
15 copy-and-paste prompts to run the same test on your own products: coredna.com/guides/prompts-a…
When ChatGPT recommended one of Australia’s most-loved retailers in our Black Friday test, the price was wrong in 15 of 24 cases.
Every wrong price was lower than the store was charging.
The retailers’ own pages were right. The answers took their numbers from elsewhere.
Where the wrong numbers came from, source by source: coredna.com/blogs/chatgpt-bl…
About 70% of experiments on YouTube’s watch page ranking model are now run by an AI system, YouTube said at RecSys 2026.
It found a new reward factor no engineer had considered, and it shipped.
The catch: left alone, the agents played it safe. They had to be told to explore.
What else we learned at RecSys 2026: coredna.com/blogs/recommenda…
The stock results in full, including three in-stock products reported as unavailable: coredna.com/blogs/black-frid…
Platypus had an adidas Gazelle at $109.99, down from $169.99. ChatGPT said A$169.99, the pre-sale price, from a comparison site.
Each time a comparison site replaced the product page and we could check it, the price was wrong. It’s the error most likely to recur on Black Friday.
Every answer where a comparison site replaced the product page: coredna.com/blogs/black-frid…










