Step 1.16: Indirect Ranking Factors
Core Concepts | Search Engines | Indirect Ranking Factors
These are things that aren’t directly looked at or even considered by Google’s algorithm, but which have an impact on or affect things that are.
For example, there is a component of a web page called a ‘Meta description’, and Google’s algorithm doesn’t look at it. But, this component has a huge impact on the CTR (Click Through Rate) of a page; and CTR is one of the most powerful direct ranking factors.
As such, it is fair to say that this class of component are a type of ranking factor, just an indirect one.