Recall this question from last week?
This is the classic "short-term optimization" vs. "long-term opportunity" question. In the short-term, you have the data that proves you are right. But you could poison the brand in the long-term by optimizing in the short-term.
This is the biggest problem I run across in my email analytics. The email guru, usually a Manager or Director, goes after short-term optimization tactics ... trying to maximize opens / clicks / conversions. After a half-decade, after a thousand messages that maximize opens / clicks / conversions via discounts, promotions, low-priced items, free shipping, and countless other games, gimmicks, and generic engagement nonsense (called 'codswallop' by some), the customer gets the message. The only customers who then respond via email are those who have been conditioned to perceive the brand as a brand that offers discounts, promotions, low-priced items, free shipping, and countless other games, gimmicks and generic engagement nonsense.
Meanwhile, the CEO is (hopefully) trying to protect the future of the "brand". As such, the CEO cannot possibly offer facts / figures that defend her point of view. She's going to argue from a position of faith.
Does the candidate side with faith?
Does the candidate side with short-term optimization?
Does the candidate offer a strategy not considered in the interview question?
The answer to the question should reveal the type of Leader this person will be. You are not just hiring this person to do a good job, you are hiring this person to protect the long-term health of your business.
In other words, the candidate better give you an answer that inspires Leadership confidence. A pithy optimization-centric answer without additional color / perspective likely disqualifies the candidate.