Configuring eVars: Choosing Allocation & Persistence

Configuring eVars: Choosing Allocation & Persistence. eVars are used as the primary custom variable in Adobe Analytics to help you gain valuable insights into the path of your client.

Configuring eVars is one of the most important parts of your implementation of Adobe Analytics. They allow us to give context to our visitors’ behaviors. For example, which campaigns drive visitors to make a purchase?

There are two critical pieces of information that we need to consider when we enable new eVars— allocation and expiry. Based on our analytics approach, these configurations will differ and have significant impact on our reporting. Should we offer the first marketing campaign that our visitors saw, or the latest, credit for purchases? How do we decide the terms of website search are most useful or hinder the quest for key content on our website?

Allocation helps establish which variable value receives credit for behavior while expiration lets you set when the value should expire.

Let’s dig into these.


Configuring eVars: Choosing Allocation & Persistence. Allocation establishes which variable value receives credit for the behavior (i.e. the conversion). We have three options to choose from: Original Value (or First Touch), Most Recent (Last Touch), or Linear, where the metric is divided equally among all values.

screen grab of allocation settings
  • Original value prevents subsequent values from overwriting the value captured. This is mainly used to link promotions to tie visitors back to their first campaign and recognize which long-term campaigns are keeping customers. We can also use Original Value to store the first piece of content viewed by our users which engaged them to stay on our website and ultimately sign up for our newsletter, or comparing the first search term or product viewed which eventually led to a purchase.
  • Linear allocation can help us to understand all the touchpoints of our visitors. Answering a question like: How are all of the products they view possess any relation to their purchase? What are all of the campaigns visitors interact with before converting? Each product or campaign will receive equal credit for our purchase or conversion. Say a visitor viewed five different product pages before placing an order — each product page receives credit for 0.20 orders. Keep in mind that this is different from participation metrics, where each variable value receives full credit.
  • Most Recent or Last touch is most commonly used for eVar allocation and can tell us the last thing our visitors saw or did before they converted, or can be used for storing IDs and information about the visitor. This can be useful in addressing the following questions: What was a visitor’s last search term before filling out a lead form? Which blog post were they reading when they subscribed to our newsletter? Last touch can also be used for values that are not likely to change, such as location or occupation information.

We can also create multiple versions of our eVars using different allocation methods. Say we configure three eVars to capture search term, one set to Original Value, one set to Most Recent, and one set to Linear.

Now, let’s compare the allocations and what search refinements they made:

depiction of path to purchase using eVars

In this example, our reporting would significantly differ based on our allocation method.

  • Using First Touch, ‘t-shirt’ receives full credit for the purchase. This can give us our visitor’s starting point before purchasing.
  • Last Touch would result in the term ‘men’s blue t-shirts’ receiving credit and tell us the search results that eventually lead our visitor to convert.
  • Linear would credit each search term with 0.33 purchases and help us to understand all touchpoints associated with this purchase.

Setting eVars Expiration

We can also decide the expiry time of variables. We can set eVars to expire after an amount of time or an event.

screen grab of expiration settings
  • Visit or hit persistence are our most popular expiration settings. Hit expiration can give details on a particular page or success event. For example, the page type or site section. Visit expiration can be useful for setting IDs to connect to our offline or CRM data.
  • Time expirations can measure short term or long term marketing effects.
  • Success events or standard events can also set the expiration setting for eVars. You may want to use an event expiration rather than hit expiration when you have steps to a funnel or form or want to track time until completion.
  • Finally, we can set our eVars to never expire. You may want to use “Never” for an ID like user ID or device ID in order to tie together all activity for a particular user, browser, or device. Use never for variables that persist the lifetime of your visitors.


If you haven’t already, go through all of your report suite settings and configurations using our Adobe Analytics Report Suite Checklist. Be sure to take a look at your current conversion variable configurations. Do your allocation and expiration settings help you to achieve your reporting goals? Which of your variables would you or should you have configured in multiple ways for comparison? Think about how these settings can alter your reporting and ultimately can affect the business decisions you make from your data.

Thank You 🙂

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