Campaign Monitor ran A/B tests for a feedback email campaign. What they did was to change the text of the call-to-action (the body of the message remained the same):
- Version A: “Tell us what we can do better” and
- Version B: “Give us your best Campaign Monitor ideas”
The result: version A clearly outperformed version B with an estimated 51% more clicks.
So do A/B tests if you can, and mind the small details, they make the design!