Mental BoundA/B testing compares versions of a thing — an ad, a headline, a landing page, a button — by splitting your audience and showing each group a different version. You measure each against a goal that matters, like sign-ups or sales, and let the numbers decide which to keep. It replaces "what we think works" with "what actually works."
The method is simple, but doing it well takes discipline: change one thing at a time so you know what caused the difference, run the test long enough to gather enough data, and pick a single success metric in advance. Tested badly, you chase noise; tested well, every change is backed by evidence.
This is where AI changes the economics. A system can generate many variants, run them head-to-head, read the results daily, and shift toward winners far faster than a manual cadence allows — the engine behind our AI-run Google Ads system. It pairs naturally with analytics that tie each test back to real return.