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Optimizely Knowledge Base

Types of metrics and when to use them

  • Create a new metric for an experiment or campaign
  • Edit an existing metric
  • Add code to track numeric metrics

In Optimizely, a metric is a quantitative measurement of a visitor action. Metrics are created out of events, which directly track actions like clicks, pageviews, form submissions, purchases, and scroll depth. After you create an event and add them to an Optimizely experiment or Personalization campaign, you'll decide how it's displayed as a metric. A simple example of a metric: an increase in unique conversions per visitor of clicks to an Add-to-Cart button; the event would simply track clicks to the button.

Optimizely's metrics builder gives you several built-in metric types to choose from when constructing your experiments. This article describes each of them, and provides examples of when to use each.

Unique conversions

The unique conversions metric tracks the number of visitors who convert. Each visitor who converts is counted only once, no matter how many times they click.

Use unique conversions when you want to track:
Demo requests
Newsletter subscriptions
White paper downloads
Event registration

Total conversions

The total conversions metric tracks the total number of conversions. While the unique conversions metric only counts the first time a user interacts with your event, total conversions will count every interaction, regardless of whether or not a particular user has already converted on a previous visit.

Use total conversions when you want to track:
Total completed purchases
Total number of upsells
Number of videos viewed

Bounce rate and exit rate

A bounce is when a visitor views only a single page on your site (in other words, if the page is the first and last page a visitor sees). If the visitor continues to browse your site after landing on that first page (in other words, if the page is the first but not the last page a visitor sees), the visitor did not bounce from the page.

If you count all of the times a page was the first page viewed (including the times it was also the only page viewed), and you divide a page's total bounces by that number, you have the bounce rate.

  1. Need use cases
  2. Should I include the platform-specific "additional considerations" from Giannis' document?
  3. Should I include information about scope?

In general, an exit is when a visitor leaves your site. In metrics, a page is an exit when it is the last page a visitor sees. Optimizely calculates a page's exit rate by dividing the total number of times a page was an exit by the number of times the page was viewed.

  1. Need use cases
  2. Is it worth mentioning that all bounces are also exits?

Please read our separate article for detailed information about the bounce rate and exit rate metrics.

Total revenue

As its name suggests, total revenue tracks the total amount of revenue generated from user interactions with your event.

Use total revenue when you want to track:
Revenue per visitor
Average order value
Revenue per visit
Customer lifetime value

In order to use the total revenue metric, you must first set up revenue tracking.

Total value

Using the total value metric enables you to quantify visitor actions beyond bounces, exits, conversions, and revenue. By selecting the total value numerator and editing a few lines of code, you can track the performance of your different variations on any visitor action that can be described numerically per conversionper session (Personalization), or per visitor (Full Stack, Mobile, and Web Experimentation).

Unlike revenue metrics, which use fixed-point numbers, metrics tracked with total value use floating-point numbers. For example, $72.81 would be submitted as 7281 as a revenue metric, but as 72.81 otherwise. Due to the dynamic precision of floating-point numbers, aggregations for non-monetary metrics are susceptible to rounding. When tracking monetary values, we recommend using the revenue metric to prevent these rounding errors.

Some common uses for the total value metric include:

What you wish to measure How you wish to calculate it

Measure reader engagement and content consumption

  • Ad units per visit

  • Ad viewability rate

  • Video play duration

  • Article scroll depth (25/50/75/100%)

  • Article page load time

  • Number of articles read

  • Number of videos watched

  • Article count per page

Measure high-value behavior beyond conversions and revenue

  • Number of items added to / removed from cart

  • Number of items per order 

  • Number of products viewed

  • Number of filters applied

  • Number of related products viewed

  • Category page scroll depth

  • Page load time

Determine appropriate products for customers based on demographic data

  • Credit score

  • Loan amount applied for

  • Interest rate selected

  • Steps of application funnel completed

Evaluate the effectiveness of website messaging and content on generating qualified leads

  • Average lead score

  • Pieces of content downloaded

  • Number of form fields completed

  • Demo video play duration

Determine booking efficacy and ability to upsell ancillary products

  • Number of items added to / removed from cart

  • Number of ancillary products purchased

  • Steps of booking funnel completed

Measure high-value behavior beyond clicks and conversions

  • Number of form fields completed

  • Video consumed

  • Unique pages per visit

  • Page scroll depth (25/50/75/100%)