Formula Inbox

Case Studies

How Formula Inbox diagnosed inbox placement failures and what it took to recover them.

Independent Book Publisher (Shopify + Klaviyo) · Independent Book Publisher (Shopify + Klaviyo)

From 30% Bounces to 62% Opens: Unwinding a 30,000-Profile List-Bombing Attack

An independent book publisher on Shopify and Klaviyo recovered from a 30,000-profile list-bombing attack that had driven bounce rates to about 30%. Campaign bounce rates fell back under 1%, open rates reached 62% to 69%, and the engaged audience recovered from about 300 to 550 to 600 readers per send.

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