Every marketer has an opinion about what their audience wants. A/B testing replaces those opinions with data. Done well, it compounds: each test makes the next campaign a little better than the last.
Test one variable at a time
If you change the subject line, the send time, and the call to action all at once, you'll never know which one mattered. Isolate a single variable so the result is unambiguous.
Start with the highest-leverage elements
Not all tests are equal. Subject lines drive opens, so they're usually the best place to start. After that, test your call to action, then your send time, then layout and imagery.
A test you can't act on is just trivia. Always ask: if this wins, what will I do differently next time?
Give the test enough data
A difference of two opens on a list of fifty means nothing. Make sure your sample is large enough that the result is statistically meaningful before you declare a winner.
Document what you learn
The value of testing accumulates only if you remember the results. Keep a simple log of what you tested, what won, and by how much. Over a year, that log becomes your playbook.
A simple testing cadence
- Pick one variable per campaign.
- Split a slice of your list between two variants.
- Send the winner to the remainder.
- Record the result and let it inform the next test.
InboxQuarry automates the whole loop: define your variants, set the test size, and we send the winning version to the rest of your list — no spreadsheets required.