What is the most I can pay to get one customer from ads?
Your maximum customer acquisition cost is capped by the contribution you earn from that customer, and a safer working limit sits well below the cap.
CAC means customer acquisition cost, the amount you spend on ads to win one new customer. Every seller asks the same question sooner or later. How much is too much to pay? The answer comes from your contribution, not from what other sellers say they pay.
Start with first-order contribution
Contribution is the price minus costs that come with the order, like product, shipping, packing and payment fee. If you have not calculated yours, read how to calculate contribution per order.
Say a first order contributes Rs 400 before ads (illustrative numbers).
If you pay Rs 400 in ads to win that customer, you break even on the first order. Pay Rs 450 and you lose Rs 50. So Rs 400 is the hard cap if you count only the first order.
Adding repeat orders
Many customers buy again. If, on average, a customer places 1.5 orders with you in their lifetime, and each order contributes Rs 400, then the customer is worth 1.5 x 400 = Rs 600 in contribution.
Now the cap is Rs 600. You can afford to lose a little on the first order because later orders bring it back.
But be careful with the number 1.5. It must come from your own order history, such as how many of last year's customers ordered again, not from hope. A new store with no repeat data should treat 1.0 as the honest figure.
Why you should not spend up to the cap
A cap is where you make no money. Spending exactly Rs 600 means you earned nothing on that customer after paying for ads. It leaves no room for refusals, returns, a customer who never reorders, or a month of poor luck.
A sensible working limit is some percentage of the cap. Say 60 percent.
- 60 percent of Rs 600 = Rs 360
- That leaves Rs 240 of every customer's value as profit and buffer
You can choose a different percentage, but choose it on purpose, and pick a lower share if your repeat rate is a guess.
Compare with your actual numbers
Total ad spend divided by new customers from ads gives your actual CAC. If you spent Rs 12,000 and got 40 new customers, CAC is Rs 300. Under Rs 360, you are inside your safe limit. Over Rs 600, you are losing money on every customer.
Careful about the new customers count. Count only new buyers who plausibly arrived because of the ad, not everyone who ordered that month.
Things that quietly shrink your cap
- COD refusals, which turn a sale into a loss. See returns and RTO, the numbers nobody tells you.
- Discount codes offered to first-time buyers
- Free shipping thresholds that push your shipping cost up
And things that raise it
- Bundles and add-ons that increase contribution on the first order
- Customers who reorder because you stay in touch by email or WhatsApp. Why email still beats every other channel for repeat sales explains how.
Write your cap and your working limit on the first page of your notebook. Whenever an ad report says the cost per purchase, compare it with both lines before you decide to scale or stop.