Backlinks Case Study: Comparative Analysis of Websites with High and Low Number of Referring Domains: Impact on Organic Search Traffic

The goal of this backlinks case study is to compare websites with a low number of backlinks with websites that have a high number of backlinks. When we say backlinks, we are talking about referring domains, or links from unique sites (only counted once – rather than talking about multiple backlinks from the same domain).

We compared the number of estimated organic search traffic the average site gets in three different groups to determine if the number of links those sites have correlates with their estimated organic traffic.

Websites were separated into these three groups:

Group 1) Averaging 101 referring domains each
Group 2) Averaging 341 referring domains each
Group 3) Averaging 1,334 referring domains each

All websites used in the case study were specific to the legal niche with preference towards personal injury law firms. We analyzed 300 websites and separated them into the three groups mentioned above, based on the number of unique incoming backlinks (referring domains) they had coming in. The sites with the lowest number of referring domains were put into Group 1. The site with the highest number of referring domains were put into Group 3. Group 2 held those in the middle.

We calculated their monthly organic traffic numbers to come up with an average monthly organic traffic for each group.

Backlinks as a SEO factor

Backlinks are important to SEO because they are looked at as “votes” by Google & Bing. When websites link to one another through the use of anchor text and content and industry-relatedness, these backlinks are used as signals help search engines understand what the page being linked to is about.

In some cases websites get natural links because of the link-worthiness of their content. In others, companies attempt to improve their search engine optimization (SEO) through link building.

This study is important for business owners to understand that a certain number of links are required for their sites to gain much organic search engine traffic. It shows direct correlation between the number of referring domains a website has and that website’s organic traffic.

Selection Criteria for Websites

The criteria for choosing the websites in this study are the following: 

– Websites in the legal industry, with a focus on personal injury law

– They are U.S. law firms from various metropolitan areas throughout the country

Backlinks Data Collection

Data for this study is collected using the Ahrefs tool. Analysis of all 300 websites determined the average number of monthly organic search visitors. This same process is used in determining the average number of referring domains in each group.

The specific metrics used were Ahefs’ RD (Referring Domains) and ST (Search Traffic) numbers. 

Data Analysis

After analyzing all 300 sites in this case study, we found that: 

Group 1’s websites had an average of 101 referring domains and averaged 383 monthly organic users. 

Group 2’s websites had an average of 341 referring domains and averaged 2,216 monthly organic users. 

Group 3’s websites had an average of 1,334 referring domains and averaged 16,777 monthly organic users.

Backlink Case Study Results

There is clear correlation between the number of referring domains and organic search traffic numbers. 

Group 2 experienced a significant growth in metrics compared to Group 1. The number of referring domains increased by approximately 237.62%, while the monthly organic users saw a rise of about 478.59%.

Group 3, when compared to Group 2, showed a remarkable jump. The referring domains grew by around 291.20%, and the monthly organic users skyrocketed by an impressive 657.08%.

The findings of this case study clearly demonstrate the significant impact that the number of referring domains (backlinks) has on the organic search traffic of websites. This correlation is critical for business owners and SEO strategists to understand, as it highlights the importance of developing a strong backlink profile to enhance online visibility and attract more organic traffic.

There is a direct, positive correlation between the number of referring domains a website has and its organic traffic. Websites with more backlinks tend to have higher organic traffic. Also, the increase in traffic is not linear but seems to be exponential. 

For complete transparency, find the spreadsheet used for this case study below containing all of the websites and Ahrefs statistics pulled Jan 19, 2024. 

https://docs.google.com/spreadsheets/d/1bPKESdmC02ikedlyMI7INnQKJjoaFUQQcXvyHg2khwU/edit?usp=sharing