Picture a home fitness brand running cold prospecting on TikTok where the top performer opens on the product in the first frame. The team wants to keep that style because it converts well on retargeting, and that's where I'd push back. A cold audience isn't looking for the product yet, so the opening has to stop the scroll on something they already feel, like a sore lower back after a day at a desk. The product can show up around second 3 or 4.
My view is that problem-first hooks should be tested on cold traffic and judged on 2-second and 6-second view rates before anyone looks at cost per purchase. Cold audiences convert slowly and the purchase data is thin early on, so view rates tell you whether the hook is doing its job well before cost per purchase has anything useful to say.
I'd side with the product-first camp on warm audiences who already know the brand. Leading with the product is fine there. Do you judge cold hooks on view rates, or do you wait for conversions?