The author's views are entirely his or her own (excluding the unlikely event of hypnosis) and may not always reflect the views of Moz.
Relevance is talked about a lot in the context of link building. In truth, it’s something that no one can really provide a concrete (or even close to concrete) answer to, because none of us knows exactly how Google measures relevance. Even having access to things like the Google Natural Language Processing API and seeing categories such as this[1] doesn’t mean that we know how Google measures relevance themselves, because there will be so much more under the hood that isn't visible to the public.
Even if we did know exactly how Google measures relevance, the extent to which they reward or penalize what they find as they crawl the web is also up for debate — like any ranking signal. We know that they use page speed, but they are also free to turn the dial on this up and down however they want.
This, in part, is why SEO is so fascinating. We’re optimizing for something that we can’t completely see and testing and refining based on the results we get. We can speculate on what Google may do or what we observe them doing, then a peer may see the exact opposite, and both may be right.
When it comes to link building and, specifically, the part that relevance plays, the potential answers are a lot more complex than we think. This is because relevance isn’t binary. We can’t just say that a link is relevant or not. We can’t say that content is relevant or not. The answers are far more nuanced than this, and we need to split things out a lot more to even begin