To determine the appropriate sample size, consider the following factors:
1. Total Subscriber List: The larger your overall list, the larger your sample size should be to maintain statistical significance. 2. Confidence Level: A higher confidence level (e.g., 95%) will require a larger sample size. 3. Margin of Error: A smaller margin of error (e.g., 5%) also necessitates a larger sample size.
You can use online sample size calculators to help determine the ideal size for your specific needs.