The Rule That Your Biggest Channel Does the Cold Work Has Never Actually Been Tested.
A widely repeated media-mix rule is stated as fact by the people who follow it. The person closest to it admits the edge case has never been tried.
A rule everyone follows, stated as a working principle
One widely repeated media-mix rule holds that whichever channel carries the most ad spend in an account is doing the genuinely cold, new-customer acquisition, while every smaller channel is mostly re-touching an audience the big channel already paid to create.
The person who states it admits the edge case is untested
Pressed live on the obvious edge case, what happens if a smaller channel actually outspends the largest one, the operator who states this rule most often admitted he has never tested it directly, and considers the risk too high to try on a live client account. The rule is a working assumption, not a proven fact, stated as one by the person closest to it.
This is exactly the kind of claim verified data could settle
Right now, the buyer community answers this question by gut and by rule of thumb, because testing it live risks real revenue on an unproven assumption. A verified, owned record checked across multiple accounts and media mixes is the kind of evidence that could actually confirm or break this rule, instead of everyone continuing to assume it.