The negative question

Ask everyone who touches marketing, separately and in writing: who is this not for?

The question is uncomfortable and that is the point. Positive positioning is cheap, because almost any statement about who you serve can be made true by being vague enough. Negative positioning costs something, which is why it carries information.

Three failure modes show up in the answers. Some people cannot answer at all, which means they believe the product is for everyone, and material written from that belief speaks to nobody in the five seconds it gets. Some give an answer that is really about size or budget, which is a qualification rule rather than a position. And sometimes different functions give incompatible answers, which means the operation is running two positions at once and the seam between them is where the leads are lost.

A good negative answer names people who could buy, might even be happy, and are still wrong for you, with a reason that would survive the sales team hearing it.

Once you have one, the test is whether anything downstream changes. If knowing who it is not for does not alter a single asset, a single channel, or a single qualification question, then it has not actually been adopted, it has only been agreed.