How to Use Ad Rotation in Google Ads for Smarter Testing

Ad rotation is one of the most underrated levers in Google Ads. It decides which ad within an ad group appears for each search — and understanding how it works can be the difference between clean A/B testing and wasted spend.

When you create multiple ad variations, Google’s rotation logic determines how impressions are distributed. Two main approaches exist:

1. Optimize: Prefer Best Performing Ads

Google uses real-time signals (keyword, device, location, etc.) to show ads expected to perform best. This is ideal for Smart Bidding or high-volume campaigns where machine learning can guide decisions.

2. Do Not Optimize: Rotate Indefinitely

Shows all ads evenly, allowing for unbiased testing of different messages or creative styles. It’s best for early-stage campaigns or controlled A/B tests where you want human-led evaluation before scaling.

When to Use Each

Use “Optimize” for campaigns focused on ROI or conversions — especially those running Target CPA or ROAS bidding.

Use “Rotate Indefinitely” for manual testing, new campaigns, or when measuring creative impact.

Best Practices

Always test with a clear hypothesis (e.g., “Discount vs. Free Shipping” headlines).

Use at least 2–3 truly different ads per ad group — not micro variations.

Once you find a winner, switch back to Optimize to let automation take over.

Integrate Google Analytics to track post-click behavior, not just CTR.

Avoid These Mistakes

Optimizing for clicks when your goal is conversions.

Leaving “Rotate Indefinitely” on too long after testing.

Running Smart Bidding with manual rotation — it confuses the algorithm.

The most successful advertisers balance manual testing and machine learning optimization — first to discover what works, then to scale it efficiently.

📘 Learn the complete framework here:

👉 https://agrowth.io/blogs/google-ads/ad-rotation-in-google-ads