<b>Running two A/B tests on the same page at once can silently corrupt both.</b>

<b>Running two A/B tests on the same page at once can silently corrupt both.</b>
If the button-color test and the headline test interact, each contaminates the other's control group. You read two clean wins that don't replicate together.
— Either run a proper multivariate test that models the interaction, or fully isolate traffic.
— Most pairs of changes don't interact — but you only learn that by checking, not assuming.
Clean-looking A/B + clean-looking A/B ≠ a clean combined launch.
Read the number, not the story. [2×2 factorial · interaction term]