What should I ask a customer when the numbers show what happened but not why?
Your numbers might show people viewing a product and choosing a familiar alternative without saying why. Pick the one decision your data can't explain, then ask a customer to walk you through a recent choice in their own words.
The creative judgment panel kept coming back to the gap between seeing a pattern and understanding a customer's decision. A representative speaking about Kate Spade described leaving the office to talk with customers, and another panelist pointed to what sales associates hear in the field. Those conversations give you questions to investigate. They don't prove what everyone wants.
Skip questions that build in the answer, like why your campaign failed or why they resisted a better option. Ask what they were trying to do, what they compared and what mattered at the moment they chose. Follow that sequence before you bring in your team's explanation.
Keep what people remember doing separate from what they say they might do next time. Both are worth writing down, but an intention isn't an observed purchase. Note how the person was recruited, because that limits what you can say.
Compare what you hear with other conversations and with the data you have. A surprising answer can justify another question or a focused test. It won't tell you the size of a market.
Then take the finding back to the decision you started with. I'd write down what the team might change and what evidence it still needs. Listening pays off when it changes the question you ask or the choice you're ready to test.