Referral traffic is Google’s method of reporting visits that came to your site from sources outside of its search engine. When someone clicks on a hyperlink to go to a new page on a different website, Analytics tracks the click as a referral visit to the second site. The originating site is called a “referrer” because it refers to traffic from one place to the next. Referral traffic is one of three statistics tracked by Google Analytics. The others are Search traffic (visits from a search engine) and Direct traffic (to a domain).
Google Analytics helps you track website activity that results from links you build, bookmarking sites you submit to and social media posts you make, such as short links from Twitter. Google looks at the source of the traffic and reports statistics about user behavior. Referral traffic also can take the form of tracking code placed on other websites, including banner ads such as AdWords, to include a referral code linked to a specific marketing campaign.
Analytics presents statistics such as bounce rate (how many people come to your website but leave without spending much time there), the percentage of visitors that are new to your site and the average time spent by users from a given referral source. According to Google, one way to figure out which traffic source is your best producer is to search for key values that are important to you. For example, if you want readers to view your articles, look at statistics such as pages per visit and time spent to determine which sources send the best traffic to your site.
Referral traffic is passed through a user’s browser, so this information is tracked and passed via the HTTP referrer. This referrer identifies where a user came from as well as where they are currently. When someone clicks on a link to your site, the browser sends a request to your server. The request includes a field with data about the last place the person visited. Google Analytics then captures this data and reports it to you as a referral domain (such as Twitter or Facebook).