The prompt, word for word
Here is an anonymised customer list. Who is in here that I would not have noticed? Look past the biggest spender. Tell me which customer is the opportunity nobody would build a campaign for, and why.
The list shape it needs
order_id, customer_ref, product, amount, date
Strip the names first. Replace them with references like C-118. It does not need to know who anyone is to see the pattern, and you should not paste customer names into a chat window you do not control.
What to look for in the answer
1. The direction of travel, not the total. Someone who started cheap and went up is worth more than someone who bought once and stopped, even if the one-off was bigger.
2. The customer who has bought three times and never complained. They are invisible precisely because they are easy.
3. Anyone your own segmentation would call low value. That label is usually about your reporting, not about them.
Why this works: most businesses already have the answer sitting in the export. Nobody has ever asked it a question. Reports get built for the customers who are a problem, and the quiet repeat buyer is never a problem.