Back-in-stock emails convert at 10-15%. That is 5x higher than your average campaign. And most stores do not have one.

When a product sells out, most Shopify stores show "Sold Out" and leave the customer with no next step. No waitlist. No notification option. Just a dead end. The customer leaves, finds the product somewhere else, and you lose the sale permanently.

Now consider what happens when you capture that demand. A back-in-stock flow lets out-of-stock visitors enter their email to be notified when the product returns. They are telling you they want to buy. They are giving you permission to sell to them. When the product restocks, Klaviyo automatically sends a targeted email to everyone on the waitlist. These emails convert at 10-15% because the intent is already there — the customer already decided to buy, they were just waiting for availability.

But it gets better. The waitlist data tells you something powerful: which products have the most demand when they are out of stock. This informs inventory planning. If 500 people signed up for a restock notification, you know exactly how many units to order. Back-in-stock flows do not just recover lost sales — they give you demand data that improves your entire supply chain.

We build back-in-stock systems in Klaviyo. Waitlist capture, automated notifications, urgency sequences, and demand reporting. Revenue you were losing to stockouts, recovered automatically.