LINE New Year Coupon Lucky Draw System: Handling High Traffic for a Chain Dessert Brand

Running an online marketing campaign, you’re afraid of too few people showing up — and just as afraid of too many!

A well-known ice cream brand has run a New Year LINE@ official account lottery campaign for five years running, letting members draw coupons through an interactive mini-game. Behind this seemingly simple flow is a technical architecture refined every single year — from keeping the system stable at peak load, to eliminating missed prize fulfillments, to optimizing the onboarding experience for non-members.

This is the fifth year Estab-Zenith has run this project, and the year its technical maturity has reached its peak.

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Campaign design: mini-game x LINE@ official account x instant coupon fulfillment

The campaign uses LINE@ official account push messages to guide players into a custom LIFF game page. On the page, players “crack open” a fortune-cookie animation, immediately drawing a matching product coupon that’s automatically saved to their member wallet.

The lottery experience flow is designed as follows:

1. Push reach: the LINE@ official account sends a campaign notification with a link into the game
2. Enter the LIFF page: clicking the link opens the custom game page
3. Game interaction: clicking “Start” automatically plays the animation, while the system simultaneously verifies the player’s identity and completes the draw and coupon issuance at this exact moment
4. Instant coupon delivery: the coupon is automatically saved to the player’s LINE member wallet, ready to use in-store. For players who aren’t yet members, the system records the prize first after a win, guides them through joining as a member, then automatically redirects them back to the LIFF page to complete coupon issuance — ensuring every winner gets their prize seamlessly.

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Key optimization: issuing prizes earlier to reduce missed fulfillments

Because the client’s coupon fulfillment runs through a third-party CRM, we identified a potential “won but never received the coupon” scenario while designing the mechanism. If the system issued the coupon only near the end of the gameplay, a player might watch the draw animation and then close the LIFF page — leaving the prize stuck mid-process, neither successfully issued nor covered by any reissue mechanism.

So we came up with an optimization: issue the prize the moment the player clicks “Start,” at the very beginning of the game — before playing the animation — while verifying identity at the same time. This whole sequence happens in one seamless motion, with no perceptible delay for the player.

Swapping the order this way moves prize issuance to before the moment the user is most engaged, drastically cutting the missed-fulfillment rate. It’s paired with a multi-trigger mechanism, so even if the connection drops mid-game, the system automatically reissues the prize the next time the user opens the LIFF page.

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Technical Architecture

• Frontend: LINE LIFF (custom game page)
• Backend: GAE with auto horizontal scaling
• Database: Google Cloud SQL, dynamically upgradable based on traffic
• Video storage: Cloudflare R2 (primary) + local server (backup)
• Coupon issuance: integrated with CRM API
• Data tracking: Google Analytics (GA4) + a custom-built lottery back office

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Results

• First-day traffic grew more than 8x year over year, and the system handled it without a hitch
• System error rate stayed under 0.01% throughout the campaign
• Five years of continuous partnership, with each year outperforming the last

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The core lesson from this project

Years of running alongside this CNY New Year promotion have taught us something clear: half of what makes or breaks a digital marketing campaign is hidden in the system architecture and process design.

A marketing campaign has a clear start and end date, but there’s zero tolerance for a poor user experience. A prize that fails to issue, an animation that freezes, a membership sign-up flow that gets stuck — any one of these can send a potential customer away disappointed, or even trigger a complaint.

The value of a long-term partnership is being able to build on every year’s observations — giving improvements a real basis and giving the next execution real confidence. Historical data is a reference, not a guarantee; true stability comes from serious review and iteration, year after year.