What is a best practice when selecting a campaign for A/B testing on bidding strategies?

• A. Choose a campaign with the smallest budget to minimize risk
• B. Choose a campaign with the highest current performance regardless of sample size
• C. Choose a campaign randomly without considering budget
• D. Choose a campaign with the adequate budget and a large enough audience for statistical comparison

Answer: (D)

When testing bidding strategies with A/B tests, you want to ensure the test has enough data to detect real differences, not just random fluctuations. That means selecting a campaign that can deliver a sufficient volume of impressions, clicks, and conversions over the test period. An adequate budget plus a large enough audience provides the statistical power needed to reach reliable results; it helps the observed differences reflect true performance rather than noise. If the budget is too small, the test becomes underpowered and you risk making decisions based on inconclusive data. Choosing a campaign solely because it currently performs well ignores whether there’s enough sample size to validate that performance. Randomly picking a campaign also ignores data quality. By ensuring both budget sufficiency and a sizeable audience, you enable a robust statistical comparison and more trustworthy conclusions.