The first project I worked for in 1997 was the creation of the website of the management school where I studied. The School was proposing several programs, bachelor degrees, master degrees, executive education… To illustrate this, we used planets, one planet per program.
In terms of SEO, I like to think of a website as a solar system. Homepage is the sun, and around it, the planets are your “pillar pages”, with in depth content about the main keywords you want to be ranked for. Just like the solar system, it’s already quite good to have half a dozen to a dozen planets: you have to choose your battles, and you cannot be well indexed on many topics. There might be some big planets, some small planets, but let’s 10 is already a fairly good number of planets. A big one will be covering a topic that will be searched more than 10.000 times per month, and a small one can be as small as 500 searches per month.
Then around these planets / pillar pages: you want satellites. Those satellites in SEO might be called topic clusters. Topic clusters are covering a topic that is in general less searched as a pillar page but that is related to it. Let’s say you cover a topic searched 10.000 times with a pillar page, one topic cluster might be searched maybe just 500 times per month and it should be around the pillar page. For example a pillar page could be “online boardgames” and a topic cluster could be “free online boardgames applications”. It’s also important to link all these cluster pages together and make them link to the pillar page they refer to.
Inspiration for this post: Creating killer content pillars.
Also cool chrome extension to discover what your cluster topic pages should be about: https://keywordseverywhere.com/