Split test subject lines

A split test sends two subject lines to a small test group, waits, then sends the winner to everyone else.

Set it up

Turn on Split test two subject lines, write Subject B, and choose:

• Test group % (10–50%): half get A, half get B.
• Wait (1–48 hours): how long to collect opens.

The subject with the higher open rate wins; a tie goes to A. Open tracking is switched on automatically for split tests.

Good tests

• Change one thing: length, a question vs a statement, with or without the name.
• Use at least a few hundred contacts in the test group for a meaningful result.
• 4 hours suits most audiences; use 24 hours for B2B lists that read mail during work hours.