Google Analytics change to setVar to affect bounce rate and time on page

Google announced on Tuesday that as of Wednesday January 27th calls to the setVar method (used to create custom segments on your site) will no longer be counted as an interaction hit.  

What is an interaction hit?

Prior to January 27th, a call to setVar would be logged as an interaction hit meaning that if it followed a call to trackPageView, the bounce rate for that page would be 0% and the time on page would be tiny, reflecting the difference between the first call and the second call.

This change is a positive move since bounce rate has long been considered a critical measure of success of marketing campaigns from all sources.  If you drive someone to a page and they leave immediately it is called a bounce and indicates that the messaging used to lure them to your site conflicts with what they were able to see when they arrived on your site (in the 8 seconds they typically spend on a given page).  Similarly if your time on page was underreported you might mistakenly waste time optimizing a problem that doesn't exist.

Who does this affect?

A significant number of people who use Google Analytics "out of the box" won't be affected by this change as setVar is only something you implement as a conscious decision to group visitors into custom segments.  If in doubt, right click on a page on your site and click view source then look for setVar in the code (Control+F will pull up a search dialog).

Why use segmentation?

You might choose to group landing pages into custom segments so you can compare the effect of landing pages on visitor behaviour.  Another common application is to use segments to label a visitor by their perceived intent.  

I might track visitors landing on my site into segments based on source to differentiate the behaviour of visitors from social networking sites from that of other referral sources.  

Why?  The custom segments extend beyond the first visit and will only be changed if the visitor receives a subsequent segment, since the last referal before a sale is commonly accepted as the key influencer.  That said, if social networking sites deliver a lot of traffic but convert poorly into sales, I can see that trend across the larger group rather than look at myspace, facebook and twitter separately.  Similarly, the bounce rate and browsing habits might be very different so I would want to isolate this behavior from paid search to make sure I'm not optimizing to a biassed crowd.

Alternatives to setVar

Google recently launched a beta program for "Advanced Segments" located in the top right of the dashboard.  It allows you to pick from pre-defined segments and create your own.  It is a subset of the functionality provided by custom segments since it only tracks visits, not visitors, but is still incredibly useful.  

For example, you can compare behaviour on the site between browsers.  Looking for patterns here like drastically higher bounce rates could mean that your site renders poorly in one browser or actually appears broken to visitors for that browser.  

I have two segments I created to identify visitors who started on my blog and another to track visitors who began their visit on my home page.  Believe me, the insight this provides may help you divert the CEO's demands to put every new toy on the home page...

I encourage you to play with the advanced segments feature, create some segments and compare behavior against the site and other similar but distinct segments to look for trends.  If you need help with this tool, of course you can contact me through the contact form on the site or leave me a question in the comments.