Key points
- A stamp card fits when customers buy much the same thing each visit. When bills vary a lot, a points program fits better.
- In the example, a free Kopi Susu Aren after 9 stamps takes Rp198,000 of spending. It costs 4.2% of that spending at COGS, or 11.1% if the cup replaces a purchase.
- Stamps per bill need a minimum spend so small bills don't count. Stamps per item fit when the reward is the same thing people buy.
- On app.kazeer.ai, stamps are added automatically when a member's bill is paid, and the cashier redeems rewards with "Tukar hadiah" (Redeem reward). Staff sign members up with the customer's consent.
Picture this: a customer buys a Kopi Susu Aren three times a week. The stamp card on their phone says 6 of 9 stamps, so they know they're three cups away from a free one.
A "buy 9, get 1" stamp card gives a reward after a set number of purchases. The reward is worth it when the extra visits bring in more gross profit than the free cups cost. So work out the target and the reward before the cashier offers the first card.
Example: Every price, COGS (cost of goods sold) figure, and sales number in this article is an example, not data from a real business.
When a stamp card fits better than points
A stamp card fits when customers buy much the same thing each visit, such as a coffee on the way to work or bread for breakfast. The rule fits in one sentence, and the distance to the reward is always in view. "Three more stamps" is easier to remember than "you have 140 points."
A points program fits better when bills vary a lot, say at a restaurant where a bill can be Rp30,000 for one person or Rp400,000 for a family. Points follow the amount spent, while a stamp per bill gives both of them the same single stamp. How to set up a points program is in the guide to member and points programs.
Before you pick a target, work out when a regular reaches the first reward. With a target of 9, someone who comes in every weekday gets the free cup on their 10th visit, after about two weeks. Someone who comes once a week gets it in week 10, more than two months in. If most of your customers come once a week, a smaller target, say 6, feels closer.
Set the target and the reward by cost
This section uses the example from the guide to COGS per menu item: Kopi Susu Aren sells for Rp22,000, with a dine-in COGS of Rp8,400. What a free cup costs you depends on how the customer uses it:
- If the cup is extra, say on a day they weren't planning to buy, it costs you its COGS, Rp8,400.
- If it replaces a cup they would have bought anyway, you lose a sale, so it costs Rp22,000.
Worked example, with 1 stamp for every paid Kopi Susu Aren:
| Target (example) | Spending for 1 reward | Cost based on COGS | Cost based on selling price |
|---|
| 6 stamps | Rp132,000 | 6.4% | 16.7% |
| 9 stamps | Rp198,000 | 4.2% | 11.1% |
How to read the second row: 9 × Rp22,000 = Rp198,000. Rp8,400 ÷ Rp198,000 = 4.2%, and Rp22,000 ÷ Rp198,000 = 11.1%.
A customer who buys a Kopi Susu Aren almost every day usually uses the free cup in place of their daily one, so its cost is closer to 11.1%. A reward from the menu that they rarely buy is more likely to be an extra.
The reward can also be a discount. A Rp22,000 discount for 9 stamps is the same as a free cup at its selling price: 11.1% of Rp198,000 in spending. A percentage discount needs a cap. 20% off a Rp300,000 group bill is Rp60,000, while with a Rp25,000 cap the discount stops at Rp25,000.
Stamps per bill or per item
One stamp per bill rewards the visit, whatever is on the bill. Set a minimum spend so small bills don't count. Without one, nine Rp8,000 iced teas, Rp72,000 in all, are enough for a free Kopi Susu Aren. That's 11.7% of the spending at COGS, or 30.6% at the selling price.
With a Rp20,000 minimum spend, one reward takes at least 9 × Rp20,000 = Rp180,000 of spending. The cost is at most 4.7% at COGS, or 12.2% at the selling price. The downside is that a group paying on one bill gets just one stamp.
One stamp per item fits when the reward is the same thing people buy, as in buy 9 coffees, get 1 coffee. A customer buying five cups for their office mates gets five stamps at once. The card fills faster, but the cost percentage stays the same, because every stamp comes from a paid cup.
Pick products or categories whose gross profit can carry the reward. If a category holds items at different prices, cost the reward against the cheapest item in it, because that's where the percentage is highest.
Inviting customers, with their consent
Offer the card before the customer pays, so their first purchase already earns a stamp. Give every cashier the same lines, for example: "Would you like a stamp card? Every Kopi Susu Aren gets you 1 stamp, and 9 stamps get you a free cup. All I need is your name and phone number. I'll send the card on WhatsApp, and we only use the number for the stamp card."
The consent rules are the same as for a points program: explain the rules before the customer agrees, ask only for a name and phone number, and move on to payment if they say no (guide to member and points programs).
Signing up for the stamp card covers the card link you send on WhatsApp, but not promotions. To add their number to a broadcast list, ask for separate permission first, as in the guide to bringing customers back through WhatsApp.
The cashier routine and the rules
So that no member's purchase slips through without a stamp, the cashier follows these steps at every sale:
- Once the order is entered, ask: "Do you have a stamp card?"
- Find the card by scanning the QR code on the customer's phone, or by phone number if they left their phone behind.
- Check whether they have enough stamps. If they do, tell them and ask whether they'd like to redeem the reward now.
- Record the reward on the same bill, so free cups don't go out unrecorded.
- Once the bill is paid, tell them their new count, for example "That's 7 of 9 now."
Write the rules on one small card by the counter: how to earn a stamp, the reward, whether stamps expire, and what the phone number is used for.
Example: Earn 1 stamp with every Kopi Susu Aren. Trade 9 stamps for 1 free Kopi Susu Aren. Stamps don't expire. We use your phone number only for your stamp card.
Stamp cards in Kazeer
Kazeer has a digital stamp card at app.kazeer.ai, as part of the members feature. The app is in Bahasa Indonesia, so the screen names below are in Indonesian. The owner sets it up under Back office > Pelanggan > Program (Customers > Program):
- How many stamps earn one reward, from 2 to 30.
- How stamps are counted: 1 stamp per bill, with a minimum spend if you want one, or 1 stamp per item for the products or categories you pick.
- The reward: one free product, a rupiah discount, or a percentage discount with an optional cap.
Points and stamps can run on their own or together.
Staff sign members up at the counter, with the customer's consent. Customers can't sign themselves up yet. After that, the cashier can send the card link on WhatsApp. The card is a web page with a QR code on the customer's phone. It shows your business name and logo, the member's first name, the stamp count such as "6 dari 9 stempel" (6 of 9 stamps), the reward, and the latest stamp dates. The phone number doesn't appear on the card, and there's no Apple Wallet or Google Wallet card.
The cashier finds the member with the camera through "Pindai kartu" (Scan card), a USB or Bluetooth scanner, or the phone number. The QR code only finds the member. Stamps are added automatically when the bill is paid, not when the card is scanned, and the receipt prints the count, for example "Stempel +1 (6/9)". The cashier redeems the reward with "Tukar hadiah" (Redeem reward), and a free-product reward needs that product on the bill. At an outlet with tax calculation turned on, a reward has to be redeemed together with at least one paid item, so put that on your rules card too.
Stamps don't expire, a bill made entirely free by a reward earns no stamp, and sales made while the internet is down get their stamps once the data syncs. A refund doesn't take stamps back, but the owner can add or remove stamps with a note.
Check the results after a few weeks
Compare the four weeks before the program with weeks 5 to 8, look at total transactions and gross profit, then subtract the cost of the rewards without counting it twice. The full steps are in the guide to member and points programs.
Example: In weeks 5 to 8, customers redeem 40 free cups. The sales lost to rewards already show in your sales figures, so subtract only the COGS of free cups not already in your report: at most 40 × Rp8,400 = Rp336,000. The extra gross profit over those four weeks has to be bigger than that.
In Kazeer, the customer list shows each member's stamps, with the filters "Hampir dapat hadiah" (Almost at reward) and "Siap tukar" (Ready to redeem). Check both once a week. Because stamps don't expire, every member under "Siap tukar" holds at least one reward they can claim any time. Multiply the number of those members by the reward's COGS to see the cost still outstanding.
- If many members are ready to redeem but don't, the cashiers may be forgetting to tell them. Remind your cashiers of step 3.
- If almost nobody is close to a reward after eight weeks, the target may be too far off, or cashiers aren't finding the member's card at every sale. Check steps 1 and 2 first.
- If total transactions don't go up, the card may only be used by daily regulars who would come in anyway, so cost the reward at its selling price.