The document discusses best practices for designing multi-channel marketing campaign tests to optimize budgets. It recommends establishing hypotheses, developing test strategies by customer segment, and creating a measurement plan with control groups, milestones, and analysis. One test found that moving a registration form to the right side of a page increased conversions by 24.6%. Another test saw a 333% increase in opt-ins for logged-in users when a "Save Now" button was added.