Personal Monopoly

Competing on a single topic puts you against everybody else covering that topic. A personal monopoly argues that the overlap of three or four things you know well narrows the field to one: a nurse who codes and reviews board games is standing where nobody else stands.

Treat it as positioning rather than a growth promise. The overlap still has to be something an audience wants, otherwise you have built a category of one that nobody is looking for. It also takes more explaining than a single-subject channel, so most of the work goes into making the combination legible in a title and a banner.