You've Probably Done This Already ...

... but I sense some in the audience would appreciate a refresher course.

Test:

• Group "A" receives all emails in the next month (i.e. 25 contacts).
• Group "B" receives some emails in the next month (i.e. 10 contacts).
• Group "C" receives no emails in the next month (0), though I realize some of you find this unpalatable, so you could make it a small number (i.e. 4, one per week).

Results:

• Measure total spend after a month, at a customer level.
• Group "A" = $25.00.
• Group "B" = $23.00.
• Group "C" = $20.00.

Adjusted Results:

• We adjust for the fact that the customer would have spent $20.00 no matter what ... that's the organic amount.
• Compared to Group "A", your organic percentage is 20/25 = 80%.
• Group "A" = $25.00 - $20.00 = $5.00.
• Group "B" = $23.00 - $20.00 = $3.00.
• Group "C" = $20.00 - $20.00 = $0.00.

From here, we can fit the relationship with a power function.

And you now know the amount of incremental demand/sales you generate at each number of contacts in the month studied. Also, yes, I understand that your analytics guru thinks this is a poor way to design a test and then measure results. No worries. It's important to be in "do something mode" in 2025.