Showing the $5.99 shipping saving at checkout raised conversions without changing order value, a sign that transparency builds trust.

Design every experiment with a primary hypothesis, ranked secondary hypotheses and guardrail metrics so a loss still explains itself.

Know the direction of a test before you run it; the A/B test measures how much, which is how Vipul's loyalty work reached 8 winners out of 11.

Converting points into dollars at the cart raised conversion 1%, brought small orders back and reduced the unredeemed points liability on the books.

Rewards work where purchase intent already exists: Quill's homepage loyalty widget drew under 0.5% engagement, while the same value on the cart page lifted conversion.