Catch the buyers
you’d lose to
sold out.

When a variant runs out, BackBy swaps “Add to cart” for Notify me when it’s back. Shoppers drop their email, you get the waitlist. Collect-only — no per-message fees, no margin trap.

Auto-flip on zero stock

The capture button appears the second inventory hits zero — no per-product toggling, no missed sell-outs.

The list is yours

Export the waitlist as CSV or sync to Klaviyo and Shopify Email. Your recovered demand, in your tools.

Never sends for you

BackBy collects — it doesn’t email on your behalf. No outbound fees, no deliverability risk on your domain.

Catch the buyersyou’d lose tosold out.

Auto-flip on zero stock

The list is yours

Never sends for you

Catch the buyers
you’d lose to
sold out.