Direct measurement:
SEMrush uses a panel made up of internet users who have installed a browser plug-in that allows SEMrush measure their browsing behavior. This panel represents internet users in general. SEMrush can use data from this panel for traffic estimations.
Referral data:
SEMrush also uses referal data to estimate website traffic. This data includes data from Google Analytics and SimilarWeb. SEMrush aggregates these data and uses them to calculate the website's traffic.
Search engine data:
SEMrush also uses data from search engine like Google and Bing to estimate website visitors. This data includes information on search queries for websites and the website's position in search engine results. This data is used by SEMrush to calculate the amount of traffic that a website gets from search engines.
Machine Learning:
SEMrush employs machine learning algorithms to analyze these data and estimate website traffic. To estimate traffic, these algorithms consider factors like the number and quality of backlinks to a site, social media shares, as well as the content of the site.
Combining data sources:
Semrush uses these data sources and methods to calculate website traffic. This is done by using statistical models to calculate the traffic to a website from the data coming from each source. SEMrush calculates website traffic by combining data from all sources. The weighting of each source data is based on reliability.
Limitations:
Traffic estimates are not always accurate. They should be considered rough estimates. Traffic estimates can be affected by factors such as website owners blocking referral information or private browsing mode. SEMrush's traffic estimates only take into account the information available and do not consider all possible sources of traffic.
Conclusion:
SEMrush estimates website traffic using a combination direct measurement, referral data and search engine data. Although traffic estimates can never be 100% accurate, SEMrush estimates are based upon a range of data sources and methods. They are useful tools for understanding patterns in website traffic.