Your inventory is talking — your marketing isn't listening. This system connects Shopify stock levels to automated Klaviyo campaigns via n8n. Overstock clearance, low-stock urgency, trending product pushes — all driven by real inventory data, not guesswork.
Products sitting 60+ days. Storage costs climbing. You don't run a clearance campaign because you don't even know which SKUs are stuck. By the time you check, the margin is already gone.
A bestseller drops to 20 units. Nobody on your team notices until it's sold out. You send a back-in-stock email 3 weeks later. The customer already bought from your competitor.
A product suddenly sells 3x its normal rate. The marketing team finds out next month in a report. The momentum is already gone. You never capitalized on it.
Every sale is "10% off sitewide." High-margin products get the same discount as low-margin ones. VIPs get the same code as first-time visitors. You're leaving money on the table every time.
Three engines running in the background. Every campaign is triggered by real inventory data, not a marketing calendar. Your stock levels decide what gets promoted, when, and to whom.
Across all three engines, the system pulls product cost, current margin, inventory age, and customer lifetime value before deciding what offer to make. No more blanket codes.
Product has 65% margin and has been sitting 90+ days. Customer has $800+ CLV. System generates a 25-30% single-use code with 48hr expiry.
Product has 55% margin, 50 days in stock. Customer is first-time browser. System generates a 15% welcome code to convert the first purchase.
Product only has 25% margin. No room for discounting without losing money. System offers free shipping instead — moves product without cutting price.
Product is trending. VIP customer with high engagement. No discount needed — exclusivity is the offer. System sends early access notification before the campaign goes wide.
| Category | Detail |
|---|---|
| Manual Process Replaced | Marketing managers manually monitoring inventory levels in Shopify, deciding when to run promotions or send alerts, exporting product lists, and triggering Klaviyo campaigns by hand — a process that introduces delays and misses real-time inventory signals |
| Trigger | Shopify inventory webhook — stock level change, new product added, product restocked, product below threshold — fires in real time |
| What the System Does | Monitors Shopify inventory in real time, detects configured inventory events, builds the appropriate subscriber segment in Klaviyo, and triggers the relevant email or SMS campaign automatically |
| Who Uses It | Shopify store owners, DTC brand operators, e-commerce marketing managers, and agencies managing Shopify email marketing clients |
| Integrations | Shopify (inventory webhooks via API), Klaviyo (segment creation and campaign/flow trigger), n8n (event routing and segment logic), Google Sheets (inventory event log) |
| Campaign Types Automated | Back-in-stock email and SMS, low-stock urgency email, price drop alert, new arrival announcement, clearance sale trigger, and flash sale activation for specific product categories |
| Revenue Impact | Klaviyo benchmark: back-in-stock emails generate an average of $3.94 per recipient — among the highest revenue-per-send of any automated email type |
| Setup Time | Complete inventory-triggered campaign system with 4 to 6 campaign types: 5 to 7 business days from kickoff to all triggers live |
An inventory-driven marketing engine is a system that connects a Shopify store's real-time inventory data to a marketing platform like Klaviyo and automatically triggers relevant email and SMS campaigns based on inventory events — rather than waiting for a marketing manager to notice a stock change and manually create and send a campaign. When a popular product comes back in stock, the engine immediately identifies subscribers who expressed interest and sends a back-in-stock notification. When a product drops below a low-stock threshold, it sends urgency messaging to engaged subscribers who have viewed the product. When new inventory is added, it triggers a new arrival campaign to the appropriate segment.
The system monitors five primary inventory events from Shopify: (1) Back in stock — a product that was out of stock now has inventory, triggering notifications to subscribers who signed up for back-in-stock alerts or who previously viewed or added the product; (2) Low stock — inventory falls below a configured threshold (e.g., under 10 units), triggering urgency messaging to engaged subscribers; (3) Price drop — a product's price is reduced, triggering an alert to subscribers who viewed or wishlisted the product at the original price; (4) New arrival — a new product is added to the store, triggering an announcement to the relevant subscriber segment; (5) Clearance — a product is marked for clearance or moved to a sale collection, triggering campaign activation.
For back-in-stock events, the system segments subscribers who: signed up for a back-in-stock notification on that specific product, viewed the product page more than once without purchasing, or added the product to their cart without completing checkout. For low-stock urgency, the segment includes subscribers who viewed the product in the last 30 days and have not yet purchased it. For price drops, the segment includes subscribers who viewed the product at the previous price point. For new arrivals, the segment is defined by product category interest derived from purchase and browse history.
Klaviyo's native back-in-stock flow requires customers to manually opt in for a specific product notification — a subscriber must click a 'Notify me when available' button on the product page. This captures only a fraction of interested buyers. The inventory-driven marketing engine extends this by also targeting subscribers who showed purchase intent through browse behavior (multiple product page views) and cart abandonment — buyers who did not formally opt in but have demonstrated clear interest. This expands the addressable audience for each back-in-stock event by 3 to 5 times.
Yes. Shopify stores many products as variants — a t-shirt in multiple colors and sizes. The system handles variant-level inventory tracking: a back-in-stock notification for a black medium t-shirt does not trigger notifications to subscribers who showed interest in the blue large version. Variant-level subscriber segmentation is maintained in Klaviyo using custom properties for the specific variant that triggered the interest event.
Klaviyo's benchmark data shows back-in-stock emails generate an average of $3.94 in revenue per recipient sent — compared to $0.09 per recipient for standard promotional emails. For a store sending back-in-stock notifications to a 5,000-subscriber segment per restocking event, that represents approximately $19,700 in incremental revenue per event. For a store that restocks popular products weekly, the annual incremental revenue from automating back-in-stock notifications alone can exceed $500,000 — revenue that would have been lost without the notification.
A complete setup with 4 to 6 campaign types (back-in-stock, low-stock urgency, price drop, new arrival, clearance, flash sale) takes 5 to 7 business days. The work involves: connecting Shopify inventory webhooks to n8n, building the Klaviyo segment logic for each event type, creating or configuring the Klaviyo flows and campaigns that fire on each trigger, and testing each trigger type with real inventory events in a staging environment before going live.
Shopify's inventory level update webhook configured to fire to n8n on any stock level change. Product and variant data included in each webhook payload.
Thresholds defined for each campaign type — low-stock threshold (e.g., under 10 units), price drop minimum percentage, restock minimum quantity — to prevent trivial inventory changes from triggering campaigns.
Segment logic built in Klaviyo for each campaign trigger — back-in-stock interest subscribers, recent product viewers, cart abandoners for specific products, price drop candidates.
Email and SMS flows configured in Klaviyo for each inventory event type. Templates written with dynamic product content pulled from the event data.
n8n receives the Shopify webhook, identifies the event type, retrieves the affected product and variant data, triggers the appropriate Klaviyo segment update and flow activation.
Each triggered campaign event logged to Google Sheets with product, event type, subscriber count reached, and campaign revenue attributed — for weekly inventory marketing performance review.
Sheets