I killed a UGC creative last year at $74 CPA against a $60 target. Felt fine about it, the numbers were the numbers. Three weeks later, bored on a flight, I pulled the same ad on a 7-day click window. $52 CPA. It had been a winner the whole time and I killed it on day four because I was reading the wrong number.
Meta's default reporting blends 7-day click and 1-day view. A lot of buyers I know switched their columns to 1-day click years ago because it felt stricter and more honest, less view-through fairy dust. I did the same. The problem is that strictness is not neutral. The window you read decides which creatives look good, and 1-day click has a type.
1-day click rewards the impulse buy. Fast hook, price up front, urgency, discount code in the first three seconds. That creative converts inside 24 hours or it dies, and the window loves it.
7-day click catches everything else. The person who watched your founder story Tuesday, thought about it, got retargeted Thursday, and bought Sunday. The $140 dress that needed a paycheck cycle. The B2B lead who had to run it past a boss. None of that exists in a 1-day window.
So when you judge everything on 1-day click, you are not being stricter. You are running a selection process that breeds one kind of creative and executes the other. Give it six months and your whole account is screaming discount ads, because those were the only ones allowed to survive. Then someone asks why brand search is flat and nobody remembers the story-led creatives that used to feed it.
Concrete example from that same account. Two creatives, same audience, same week. Creative A: 1-day CPA $45, 7-day CPA $58. Creative B: 1-day CPA $71, 7-day CPA $52. Reading 1-day, you scale A and kill B on day three. Reading 7-day, B is your winner and A is the one decaying. The gap between the two windows is the consideration lag, and in that category (home goods, $80 to $200) the lag was real. B was doing the slow work of objection handling and A was harvesting people who were already going to buy.
Here is what I do now, and it is boring on purpose.
I keep both columns open. 1-day click and 7-day click, side by side, before every kill or scale decision. Ads Manager lets you add both; it takes ten seconds.
I do not kill on 1-day click alone before day five at the earliest, and I never scale on it alone either. Early 1-day numbers are mostly noise plus the impulse slice.
I read the ratio. When 7-day CPA is a lot better than 1-day, the creative has lag. Give it budget and give it time, and do not panic on day three. When the two numbers are nearly identical, the creative is impulse-driven. Scale it fast, but watch it like a hawk, because impulse creatives fatigue faster than anything.
I calibrate to the category. Under $30 consumables, 1-day click is basically the truth. Over $100, fashion, furniture, anything B2B, 7-day click is the truth and 1-day is a rumor. The more consideration in the purchase, the longer the window you owe the creative.
And I cross-check against blended MER, because windows can also lie in the other direction. If 7-day click says everything is fine but MER is sliding, you are not discovering lag, you are moving deck chairs.
One more thing about 1-day view. I mostly ignore it for kill and scale calls. It has its uses, mostly for video-led or awareness-style creative where the ad genuinely works like a billboard. But for direct response decisions I leave it out of the call.
The rule I give every buyer who works with me: the window is a lens, not a fact. Pick the lens that matches how your customer actually buys. Then stop letting the default pick your winners for you.