Over the past five years, our team at Perficient has conducted continuous studies to evaluate the lasting impact of links on rankings. These studies consistently show that links matter as a ranking factor, but they also show that Google is dialing up their emphasis on the quality/authority of those links. We can say this because of the strong correlation our most recent studies show between the Domain Authority (DA) and Page Authority (PA) of linking pages and the rankings of pages receiving the links.
Each year, Moz has graciously provided us with access to their Link Explorer[1] index, where we obtain the raw data to perform our analysis. In these studies, we perform Spearman Correlation analyses to show how the following variables correlate with ranking:
- Number of links to the ranking page
- DA of links to the ranking page
- PA of links to the ranking page
Please note that Moz has never compensated us for including, or asked us to include, the DA and PA calculations — we have chosen to do that of our own volition. In fact, Moz staff only learned that we had done so in early October of 2020, even though we published the post with our findings[2] on April 16, 2020 (to be honest, I was too busy to catch up with the Moz team and let them know). In short, there is no quid pro quo here.
Study methodology
Go ahead and jump down to the study results section if you just want to see how things turned out!
We have been conducting this study on a nearly annual basis since May of 2016. In 2016, we started with an initial query set of 6K queries, but have expanded to 32K queries over time. The queries were obtained