Are you just starting off with Adobe Analytics? Well, it's great that you're here to learn about props and eVars.
In addition to the out-of-the-box dimensions and metrics, Adobe offers these two custom variables to complement your basic tracking. Props and eVars are really the meat-and-potatoes that makes Adobe Analytics tracking so flexible.
Each of them have its own unique purpose, so let's get familiar with how they're used.
What are props?
Well, props are custom traffic variables that are meant to be counted every single time. The metrics that complement traffic variables are page views or instances, visits, visitors, etc. We normally use props to understand how many times a given action has been performed.
For instance, if the same button lived on 10 different pages and a user clicked on all 10 of them, you'd get a count of 10 for that single prop variable. Props fire every single time incrementally, and are not persistent. Nothing else can be correlated with the single prop if it didn't fire at the same time.
When to use props
You can use props to measure additional page engagement, such as button clicks or video views. It'll help you see which elements people like to use to navigate through your website. With Adobe's current updates, they suggest using eVars now in place of props as they have custom expiration rules.
Capture List Values
By using the list s.prop variable, you're able to capture multiple values at once. This is especially helpful when users are selecting multiple items or viewing multiple products.
How to correlate a prop with an eVar
One common mistake that I normally ran into was creating a HIT segment to capture the prop. Because the prop fires only at the page-level, you need to make sure the prop is tagged or even exists on target pages. Otherwise, nothing will appear when you apply the segment.
In order to capture the prop that happened on another page within the same visit or by the same visitor, you'll need to expand the segment to the User or Visit level. Then you'll be able to see how many encountered the prop within their session or user lifetime.
Let's take this for example. We want to see if clicking a banner on the home page ever influenced a conversion later in the same visit. You can create the segment as such:
VISIT = CONTAINER (HIT = Page contains "home page" AND HIT = LinkName contains "banner") AND CONTAINER (HIT = Page contains "order confirmation")
So in this case - in a single session, a user hits a banner ON the home page at one point and also hits the order confirmation page at another point. The order isn't specified here, but as long as they completed these two touchpoints, the user will be included in the data set. Also, another thing to note is the separate containers. By separating the two HIT's, each action is separated from the other. Because really, it's not possible to reach the home page and the confirmation page in one click.
What are eVars?
eVars are custom conversion variables linked to success events (aka your website goals), so they persist through the entire session without having to fire multiple times. As long as they are fired once, it gets attributed to other success events to the same cookie (aka user). You can set a custom expiration rule to any time frame or behavior style, and even make it act like a prop if you'd like.
One widely used example is when a user logs in, the eVar fires once at initial sign in and will “follow” the cookie wherever it goes. If you're an ecommerce business, eVars are automatically linked to Orders, Transactions, and other ecommerce metrics. So the example segment I described above under props is unnecessary. You'll just need to navigate to the custom eVar report and select the metric you want.
When to use eVars
Almost any conversion instance you can with the knowledge that you're limited to 75 or whatever your subscription allows. Some examples include shopping funnel steps, lead form steps, and any even user attributes that would only fire after login to persist through the entire session. The general rule is to set an eVar every time you set a prop - because the two don't mix unless you use a segment by Visit or Visitor of course.
If all this segment talk is foreign to you, check out this article to get you familiar with Adobe segments asap.