Do you have mirrored or forwarded domains and wondered how this might affect your Google Analytics data? In this post we will explore what might be occurring in your reports.
What is a Mirrored Domain?
A mirrored domain is any additional domain name that a visitor can use to access your website. It is called 'mirrored' because the website and it's content is identical even through it is a different domain name.
Mirrored Domains and Google Analytics
For example, you visit your website, then click 'about us' and then 'contact us' and the URLs you see in your browser are;
Then you have another domain, in this example we will use www.yoursite.com.au and you browse the same page;
When you browse this mirrored site all the content is the same, which means that your Google Analytics tracking code will also be the same because the whole site is an identical copy (or mirror).
This example used .com.au as the mirrored domain (for the Australian version of our site), but your site might be mirrored under a totally different domain. For example www.myproduct.com could have the exact same content as www.yoursite.com if it is mirrored.
If you are not sure if your site is mirrored talk to your web developer, they will be able to let you know if your site is mirrored or not.
If you do have a mirrored domain (or domains) then this generally isn't a problem for Google Analytics reports, people will simply access one site or the other, data is collected and then reported.
However, you should consider the following scenario; lets say a new visitor clicks a link on another website and comes to www.yoursite.com, this will be reported as a referral in Google Analytics. Then if they do a search on Google and visit www.yoursite.com.au they will be seen as an organic visitor (i.e. coming from a free search). As these are two separate domains, Google Analytics will use two sets of cookies, so the visitor will be seen as two different visitors within the reports.
If you wanted to see the organic search that resulted in the visit to www.yoursite.com.au as a returning visit, rather than a new visit you will have to remove the mirrored domain. You can do this by redirecting one website to the other (check with your web developer so this is done properly). Then you will only have one cookie for the site and remove the additional cookie.
When Mirrored Domains Cause Problems
Mirrored domains will cause Google Analytics data issues when someone can navigate between the domains within a visit to the site.
For example, if someone comes to www.yoursite.com and then there is a link within www.yoursite.com that goes to www.yoursite.com.au. If this occurs then www.yoursite.com will become a referral to www.yoursite.com.au because each domain has its own set of cookies.
This will also mean that if someone accessed www.yoursite.com via a search (or referral or any other method) and then ended up converting (i.e. goals or ecommerce) on www.yoursite.com.au the credit would go to the www.yoursite.com referral and you will loose the ability to see the actual source and medium that got you the visitor in the first place.
This is a major issue and the way to correct it is by setting up cross-domain (or multiple domain) tracking. This will be further complicated if people can then travel back to the original site, for example they land on www.yoursite.com, then navigate to www.yoursite.com.au and then back to www.yoursite.com. This problem can also be solved by correctly implementing cross-domain tracking on both the domains.
Forwarded Domains and Google Analytics
A forwarded domain is a domain that redirects you to your primary website. For example, lets say your primary website is www.mysite.com and you navigate to 'about us' and then 'contact us', the URLs will look something like this;
Then you have another domain, in this example we will use www.forwardsite.com that forwards to www.mysite.com. When you access www.forwardsite.com you will instantly be redirected to www.mysite.com and you will continue to navigate as normal;
http://www.forwardsite.com (instantly redirects to www.mysite.com)
In this case Google Analytics will never report on www.forwardsite.com if you are using this domain in particular marketing or promotions you may want to setup Google Analytics campaign tags on the URL that is set as the redirect (this is something your web developer will have to help you with).
The forward settings for the example above would have http://www.mysite.com as the domain to forward visitors to. You could then use campaign tags to attribute the visitor to the www.forwardsite.com domain that they originally used, for example the forward domain could become something like;
This would allow you to see how many people are using the www.forwardsite.com URL to get to your primary website.
If you have mirrored domains you may have data inaccuracies due to the different sets of cookies, so consider the options and make sure you have accurate data to base your decisions.
If you have forwarded domains then you probably don't have anything to worry about, but you might want to get insight if you are using the domains for marketing and promotions.