How it works: The system sends Version A to 10% of the list, Version B to 10% of the list. It waits 4 hours. It sends the winning version to the remaining 80%.

Variables to test:

• Subject Lines (Most common).

• Send Time (Morning vs. Evening).

• Button Color (Red vs. Blue).

• Sender Name (“elearningshub” vs. “Kerry from elearningshub”)