Secondary dimensions can be added to just about every Google Analytics report from the Secondary dimension dropdown menu - just above the first column of data. Secondary dimensions enable you to drill down further into the dataset by applying a second level of information.

Explaining Google Analytics Secondary Dimensions

According to Google, the Secondary Dimension feature allows you to define a primary dimension and then view that data by a secondary dimension within the same table.

That's a mouthful! Let's translate it for you. Primary dimension is a fancy way of saying the main focus of the report. So, the focus of the report, chosen from the left sidebar navigation menu in Google Analytics, is your primary dimension.

The secondary dimension is simply an additional piece you select for a more granular view of your report data.

Secondary Dimension Example

Let's cement the concept in an example. You're a busy content marketer managing the business blog. You are auditing Google Analytics to understand the landing pages driving the most website traffic, and want to know how much of that traffic, on each of the most popular pages, is coming from a mobile device.

First, you navigate to Content > Site Content and select Landing Pages (our primary dimension).

Then, from the "Secondary dimension" drop down menu we chose Mobile (Including Tablet).

You can see that Secondary Dimension Mobile (Including Tablet) is now sandwiched between Landing Page and Sessions. This is standard placement for the secondary dimension so you can immediately see how it relates to your primary dimension.

The Secondary Dimension Mobile (Including Tablet) indicates whether or not visits were from mobile and tablet devices in a yes/no format. Looking at "/" in our example, indicative of the website homepage, you'll see 7007 sessions were derived from a non-mobile device, but 1847 sessions (approximately 5% of the overall traffic) came from a mobile or tablet device.

What does this mean for you? Now, you can easily see that for the specified time period, the majority of traffic is coming from a non-mobile source. It means you have access to facts that support your current business decisions and help you make strategic and tactical decisions that affect the future health and growth of your company.

Secondary Dimensions Takeaways

I'm sure your head is reeling with a ton of ideas for applying secondary dimensions to your Google Analytics data. Go ahead get your hands dirty and experiment to see what yields the best results.

When you need detailed information about the business impact of your data, anecdotal information won't cut it. To gauge the effectiveness of what you're doing online you need the facts. Use secondary dimensions to give you the context you need to make sound business decisions.