Write the kill rule before you look at the numbers

Description and use

Set kill rules in advance to avoid prematurely shutting down good channels and keeping dead ones alive.

Problem

Decisions about marketing channels are often made after seeing data, leading to premature termination of good channels or prolonged support of bad ones.

Outcome

Implementing pre‑registered thresholds reduces decision bias, ensures consistent evaluation, and improves resource allocation across marketing channels.

Workflow

• 1. Identify the channel to evaluate.
• 2. Write a kill rule: "If fewer than N results after X units, the channel is out."
• 3. Write a keep rule with corresponding numbers.
• 4. Record the rules and the date to review results in a file.
• 5. Do not alter the rules until the review date.
• 6. On the review date, compare results to the thresholds and act accordingly.

Evidence

If fewer than N results after X units, the channel is out.

Source

Both are the same error: deciding after seeing the data instead of before.

Source