Using Custom Variables vs. Segmentation [Adobe Analytics]
As I work with and train clients to use Adobe Analytics, sometimes I encounter confusion around custom variables and segmentation. Both of these Adobe Analytics features are used to segment data, but they do so in different ways. In this post, I am going to take a step back and discuss how to think of these different product features in the proper context when doing analysis.
Custom Variables
So what exactly are custom variables? In daily use, Adobe Analytics custom variables are dimensions, taking the form of conversion variables (eVars) and Traffic Variables (sProps). Each implementation gets a specific number of these custom variables in addition to the ones that are provided out-of-the-box. These variables are used to track specific data elements that are meaningful to your organization. For example, if you have visitors log into your website (or mobile app), you may decide to allocate an eVar to the User ID and pass that ID upon login. By storing this value in an eVar, any activity from that point forward can be associated with a specific User ID. The choice to use an eVar vs. an sProp depends on a few factors including how long you want the value to persist, whether you need Pathing, etc. Additionally, you can use the various expiration settings to determine for how long the User ID will be retained in Adobe’s virtual cookie.
However, one downside of custom variables is that activity is only tied to their values from the time they are set and afterwards. For example, in the scenario above, it could be the case that a visitor viewed twenty pages on the website prior to logging in and providing their User ID to the eVar. In that case, all of the activity from the first twenty pages will not be associated to any User ID. Therefore, if various Success Events are set (i.e. Cart Add, File Download) during those initial twenty pages, they would appear in the “None” row of the User ID eVar report. Unfortunately, over the years, I have seen that many Adobe Analytics customers don’t understand this nuisance, which is pretty important.
Ideally, you set as many of your custom variables as early as you can in the visit, but there will always be cases in which Success Events occur prior to an eVar receiving a value. Let’s illustrate this with another common example. Imagine that a visitor visits a B2B software site, views a bunch of products and eventually views the pricing page for a CRM product. Based upon the fact that they ended up on the pricing page of the CRM product, your marketing team chooses to assign a value of “CRM Prospect” to a “Marketing Segment” eVar. Hence, from that point forward, you can see all website activity for “CRM Prospects” by using the “Marketing Segment” eVar, but what about all of the activity that these people did before they were assigned to this segment? Up until that point, they were anonymous as far as that eVar was concerned. For example, if you were to create a Conversion Funnel report in Adobe Analytics and filter it by the “Marketing Segment” eVar value of “CRM Prospect,” you would only see filtered Success Events that took place (were set) after the eVar had been populated with the value. This can create issues at times and lead to real confusion.
In all of these cases, the common theme is that custom variables are useful, but sometimes don’t show the complete picture. Next we’ll talk about how using Segmentation can help complete the picture.
Segmentation
As you hopefully know by now, the Segmentation feature within Adobe Analytics allows you to narrow down your data set to only those hits, visits or visitors that meet the specific criteria you have added to your segment definition. This feature allows you to instantly focus your web analysis on the exact population you care about. As you would expect, the segments you create can use out-of-the-box data elements or any of the aforementioned custom variables. However, the reason why Segmentation is so powerful is that when you use a Visit or Visitor based segment, you are able to include all of the data that took place within the session (or beyond if using a Visitor container) instead of just the data that took place after a value was set in a custom variable.
Since this can be confusing, let’s use one of our previous examples to illustrate this. Imagine that you are interested in seeing the internal search phrases (stored in an eVar) used by visitors in the “CRM Prospect” segment, which uses the “Marketing Segment” eVar describe above. If you were to open the “Marketing Segment” eVar and find the row for “CRM Prospect,” you could then break this row down by the internal search phrase eVar (possibly using the “Internal Searches” Success Event) and see all of the search phrases used by that group of people. However, as explained above, you would really only be seeing the search phrases that were used after people were identified as being in the “CRM Prospect” segment. It is possible that some of the folks who eventually got placed in to the “CRM Prospect” segment conducted searches for various phrases prior to them being added to the segment. Therefore, using the custom eVar may not give you the entire picture.
If you want to be more thorough, in addition to using the custom eVar, you can rely on Segmentation to get your answer. In this case, you could create a segment in which the Visit contained a “Marketing Segment” eVar value of “CRM Prospect.” This means that Adobe Analytics will look for any activity that took place in the entire visit in which the “CRM Prospect” value took place. This segment would include all of the activity after the eVar value was set and the activity that took place before it was set. Once you apply this segment, if you open the internal search phrase eVar, the values in the report will, by segment definition, include all of the search phrases conducted by people who at some point were added to the “CRM Prospect” segment [for the advanced folks, you can even use exclude containers to take out any other segments if you want to be exact]. Therefore, the data you will get back using the custom variable approach may not be as complete as you would get back using the segment approach. This becomes even more potent if you use a Visitor container in your segment since that will include data from all visits in which a visitor was placed into the “CRM Prospect” segment.
Final Thoughts
While this topic can be a bit confusing to novices, it is something that is important for your end-users to understand. I often find that end-users are not properly trained on how to use Segmentation to its fullest extent and, therefore, many end-users rely solely on custom variables. This sometimes means that they are not getting the full picture when it comes to data analysis. It is for this reason that I suggest you read this post a few times and teach your users how custom variables really work, including what happens before and after they are set and how using Segmentation differs. You will probably end up seeing a steep increase in the usage of Segmentation as a result!
