What is the minimum number of contacts needed to effectively run an A/B test?

To effectively run an A/B test, a minimum number of contacts is crucial to ensure that the results are statistically significant and reliable. While there may be no absolute minimum that applies universally to all scenarios, having 1000 contacts is generally seen as a baseline that allows for proper segmentation and enough data points to evaluate the performance of different variations effectively.

With 1000 contacts, you can split your audience into two groups—one for each version of the email—while ensuring that the sample size is large enough to detect differences in key performance indicators, such as open rates and click-through rates. A smaller sample might lead to results that are heavily influenced by random chance, making it difficult to draw accurate conclusions about the effectiveness of the email variations.

Going beyond 1000 contacts can provide even greater statistical power, but 1000 is a widely accepted starting point for most A/B tests in email marketing. Therefore, maintaining this minimum helps marketers achieve more reliable and actionable insights from their testing efforts.