Real expertise
A writer can stand behind the lane, not just write around it.
The niche has to be one a named author can credibly inhabit — a work history, a current practice, or a verifiable track record a reader can check. We score it on the depth of the lane the operator already lives in: a part-time enthusiast rates lower than a ten-year operator, even on the same topic, because the byline bar is what the next Helpful Content update grades against. A niche that requires faking expertise to publish isn't a Braidpost niche.
Commerce potential
The reader has a wallet open and a comparison to make.
A niche scores on whether buyers actually transact inside it — affiliate programs, ad RPM, sponsorship pipelines, or a paid product a reader would buy. We map the merchant landscape per lane and take a share of the demand signal we can actually serve, not the size of the topic. A large topic with no commerce shape (and no path to one) fails this bar even if the SEO curve is real.
Defensibility
The site holds rank and rail share against new entrants.
A niche scores on the moat a launched site can build — the named-author bar, an editorial cadence competitors can't replicate, and a content map the algorithm has to reward. Defensibility is the thing that turns a six-month spike into a multi-year lane. A niche that can be flattened by an aggregator launch or a thin-AI copycat scores low even when the demand curve points up.