#1 Code missing on some pages of your site
According to Google's guidelines for integrating Google Analytics code, you "copy and paste the code snippet into your web pages." Checking for this snippet may be easy on smaller domains but can be easily overlooked on complex websites.
If you are running a CMS then you can place the tracking code in your template file(s) or by using a plugin (lots of open source CMS’ have Google Analytics plugins available).
To ensure that your Google Analytics tracking code is installed, you can perform an audit. We recommend using our tracking code audit tool within Analytics Checkup.
#2 Subdomain(s) require code changes
A common error is only adding the modified tracking code to the subdomain or vice versa. The idea behind adding the setDomainName line to you code is to pass on the cookie values when visitors travel between your main site and the subdomain(s).
To track subdomains correctly modify the tracking code appropriately and then apply the modified tracking code to your main site (e.g. www.company.com) and your subdomains (e.g. news.company.com).
#3 Not tracking campaigns
If you are running Google AdWords campaigns, you don't have to worry about tagging your URLs as this happens automatically after you have linked Google AdWords and Google Analytics. All your AdWords traffic will then appear as “paid” (or CPC) within Google Analytics.
If you have other paid campaigns (i.e. non-AdWords), they will appear as referral traffic by default. Therefore, you must tag your URLs with parameters in order to fully understand which individual campaigns are driving visitors to your website.
To tag your campaign URLs, we suggest using our campaign tag creator tool within Analytics Checkup. We recommend you campaign tag as many of your marketing and advertising initiatives as possible to accurately see how people are finding your site.
#4 Not excluding internal traffic
Often your site is visited by your employees and web development providers. However, this traffic is going to appear as highly engaged without resulting in any website conversions. This is also going to skew your analysis.
We recommend creating a profile-level filter that excludes your internal IP addresses so you have a profile with more accurate data for analysis.
#5 Not tracking your offline campaigns
If you are running offline campaigns to promote your website we recommend you set up a special landing page for that campaign. For example;
Then campaign tag the landing page URL. For example;
And finally, ask your web developer to setup a redirect to your tagged URL. For example;
Setup www.company.com/brochure to redirect to www.company.com/offline-landing-page?utm_source=brochure&utm_medium=offline&utm_campaign=brochure-promotion
Now you can track the effectiveness of your offline campaigns in driving people to your website.