setVar Change Impacts Bounce Rate in Google Analytics

Google Analytics has announced a change to the custom variable _setVar, which will impact key metrics such as bounce rate and time on page. In this post I will try to shed some light on setVar and bounce rate, and show a few examples of where we can use them to gain insights if our visitors’ behavior.

What is _setVar in Google Analytics?

User Defined Reports in Google Analytics

_setVar is a custom variable Google Analytics can read, which enables us to send Google Analytics certain data which is not predefined in google analytics and may be relevant for our reporting needs. Popular examples are differentiation between user’s status (logged in vs. not logged in), male vs. female and whatever else variables we want to segment our traffic on. This can be done with values submitted via forms (username, gender, age group etc.), saved in cookies etc.

All the website owner needs to do is to call the javascript (below the GATC code):
<script type=”text/javascript”>pageTracker._setVar(‘logged in’);</script>

_setVar values are collected into a special report in Google Analytics which can be found under Visitors > User Defined.

Known Limitations of _setVar:

  • You can only send one variable, so you are somewhat limited in the customization here. There is a workaround John has posted for this at lunametrics.
  • Use of _setVar creates a second instance of Google Analytics one each page, which has lead GA to reduce the bounce rate significantly on pages with _setVar. This Changed yesterday (explanation below).

Some more info from Google help

What is Bounce Rate in Google Analytics

Bounce Rate is best defined as a “bad” visit. It is a quick qualifying metric which determines whether a visitor has acted or not. The basic assumption is that we want our visitors to engage with the websites and pages thus to consume our information, click on links, download stuff, buy stuff etc.
Bounce rate is determined where a visit occured and none of the above interactions occured afterwards:

  • Pageview
  • Action
  • Transaction
  • Experiment (Google Website optimizer)
  • User Defined Call (_setvar) – will no longer be considered interaction for this calculation.

The true meaning of bounce usually show low interest in a landing page for the bouncing visitors. Bounce Rate is one of the most powerfull fast-metrics we use to find good and bad traffic sources, as well as pinpoint landing pages needs to be improved.

Some more info:

The Change and its Impacts

The recent change changes the way bounce rate is calculated. Bounce Rate will no longer consider a user defined interaction (calling _setVar) in the calculation. The major impact for users who call the user defined finction will be an INCREASE in the bounce rate.

So is it good or bad news?

In my humble opinion this is great news. This change is based on a lot of comments from Google Analytics users and experts around the globe, and reflects Google’s ability to listen and improve their software accordingly. Moreover, the change will simply mae our analysis better and more exact than it was before.

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