Listicle

Seven mistakes, twelve tools, five settings. The structure is popular because it is straightforward to write, easy to skim and honest about its length, and the viewer always knows how much is left.

That last property cuts both ways. A numbered list invites people to jump ahead, so the ordering matters and every item has to be worth stopping for, which usually means holding something strong back for the end. The weakest version pads to a round number. Ten items where six were good tells the viewer that the count came first and the thinking came second.