Impressions Overview

In Angelfish, Impressions are used to track items that have been opened or viewed, like:
  • emails
  • images on remote websites (ads)
  • in-site promotions

Impressions are tracked by requests for filenames that contain Marketing Variables (MVs).  Impressions are available with External MVs and Internal MVs.

Here's a quick explanation of how this works:
  • Add a small tracking file to your website, a.k.a. an Impression File
  • Reference | embed the Impression File (with MVs) in the item you want to track
  • The Impression File is requested when the item is viewed
  • During processing, Angelfish detects the Impression File & MVs
  • The MV parameters specified in the Advanced tab of each Profile are used to detect Impressions and MVs.

Specific examples of Impression tracking are in the Examples section, below.

Key Concepts


Angelfish has 2 types of MVs: Internal and External.  Impressions use MVs to match up with Visits.

Internal MVs have 3 required parameters:
  • Internal Campaign
  • Internal Medium
  • Internal Variation

External MVs have 3 required parameters: 
  • External Source
  • External Medium
  • External Campaign

As a reminder, you can configure Angelfish to use any query parameters as MVs.  This includes campaign variables from Google Analytics.

When adding MVs to Impressions:

Internal Impressions require all three Internal MV parameters:
  • Internal Campaign
  • Internal Medium
  • Internal Variation

External Impressions only require two parameters
  • External Source
  • External Medium

A Hit that matches the "Impression File Types" setting and contains Marketing Variables.  A Hit that contains MVs can either be an Impression File or a Page, not both.

Impression File Types are configured in the Settings tab of each Profile.  Impression File Types are typically image files: png, bmp, jpg, jpeg.  

Impression Files don't need to be unique - you can use one Impression File to track Impressions for all your marketing initiatives.  Just change the MVs used in each Impression File reference to match the item being tracked.

Here's an example of an Impression File (with MVs), used in the Demo Profile to track email opens:

A numeric value that shows the number of times an Impression File was requested.  The Impression Metric is shown in the reports for Impression Files, and in reports for the MVs represented in the Impression File request.

Impression Examples

  • The following examples are for a fictional website: intranet.corp
  • Each example uses the same Impression File (impr.jpg) with different MVs
  • Impressions can be used to track a variety of items, and are not limited to these examples 


  • Monthly newsletter, sent to internal staff

  • Emails bring inbound Visits to your website.  Only use External MVs when tracking email opens.
  • Embed one Impression File in the email to indicate when the email is opened.
  • Use External Source, External Medium, & External Campaign in the Impression File reference
  • Emails can contain multiple links.  You only need one Impression File for the email, not one for each link.
  • Each link in the email needs the same MVs as the Impression File, plus Variation

Impression File Reference:


  • Banner image files promoting an upcoming company event, 3 different images are used
  • Images are shown on various Intranet websites (site1, site2, sites3)

  • The images bring inbound Visits to your website.  Only use External MVs for this scenario.
  • Use External Source, Medium, Campaign, & Variation in the Impression File reference
  • The inbound links for each image need the same MVs as the Impression File, plus Variation
  • Edit the Source to reflect the website where the image is shown
  • Use Goals with External Variation to A|B test the different images

Impression File References:


  • The main page of intranet.corp has an image slider above the fold
  • You want to compare clicks & views for the last image in the slider 

  • Visits are already on intranet.corp: use Internal MVs for this scenario
  • The link for the image needs the same MVs as the Impression File, plus Variation

Impression File Reference:
Creation date: 4/18/2022 7:08 PM      Updated: 8/29/2023 4:20 PM