Most Amazon brands evaluate ad performance at 30 days. Maybe 60. Ambitious ones
By Adam Weiler · November 10, 2026 · Curated by George's Blog
Most Amazon brands evaluate ad performance at 30 days.
Maybe 60. Ambitious ones push to 90.
Then they make budget decisions based on that window.
Here's the problem with that.
ACoS at day 45 is an incomplete picture. It doesn't account for what that customer does in months 2 through 12.
And for repurchasing products... that's where most of the money lives.
A product that looks like a loser at 45-day ROAS can be a monster by month 12 once repeat orders stack.
So the question isn't what did I spend vs. what did I make this month.
The question is: for every dollar I spent acquiring that customer, how much did they give me over the next year?
Here's what that math can look like in practice.
You spend $1 on ads. At month 12, you get $4.80 back in revenue. Your actual profit back at month 12? $1.74 per dollar spent.
That changes everything about how you think about budget.
Because now the question isn't "is my ACoS good this week?"
It's "what's the right CAC given my 12-month return, and am I spending enough?"
Two completely different questions. Two completely different strategies.
Brands optimizing for short-window efficiency often underinvest in ads that would have printed money at month 12.
They cut the best performers early because the early numbers look thin.
LTV-to-CAC is the metric that catches that.
Do you currently measure ad performance beyond 90 days, and has it ever changed a budget decision?