How many variants to test
The number of variants you can meaningfully test depends on your audience size and primary metric.
Guidelines by audience size
| Audience per send | Recommended variants | Primary metric |
|---|---|---|
| 5,000-20,000 | 2 (control + 1) | Open rate or click rate |
| 20,000-50,000 | 2-3 | Conversion rate |
| 50,000-150,000 | 3-4 | Revenue per exposure |
| 150,000+ | 4-5 | Revenue per exposure |
Why fewer can be better
Each additional variant dilutes the traffic per variant, requiring more exposures for a definitive verdict. Two well-designed variants that test a clear strategic question will produce more actionable insights than five variants with minor copy differences.