Definition
Custom event tracking in email records specific subscriber actions that go beyond the default metrics of opens and clicks. While every email platform tracks basic engagement, custom events allow marketers to define and measure actions like watching an embedded video, completing a form, scrolling past a certain point, interacting with a poll or saving an offer to a wishlist.
These events are typically implemented through tracking scripts on landing pages, interactive email elements or third-party analytics integrations that communicate with the email platform's API.
Common Custom Events
- Video play, pause and completion
- Poll or survey response submission
- Scroll depth milestones within the email body
- Add-to-calendar or save-for-later actions
- In-email search or filter interactions
- Offer reveal or coupon activation
Why It Matters
This matters because the choices you make here show up directly in your results. These events are typically implemented through tracking scripts on landing pages, interactive email elements or third-party analytics integrations that communicate with the email platform's API. When this is handled well it supports engagement, delivery, and the trust subscribers place in your brand; when it is neglected, the effects tend to show up in declining performance and harder-to-fix problems further down the line.
Best Practices
- Track only events that have a clear link to business outcomes — tracking everything creates noise
- Name events consistently across campaigns so historical analysis is possible
- Use custom events to trigger automated follow-up sequences rather than relying on opens and clicks alone
- Combine custom event data with subscriber profiles to build richer segmentation criteria
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Related Glossary Terms
A/B Testing
A/B testing in email marketing is the practice of sending two variations of an email to a small sample of your list to determine which version performs better before sending the winner to the remaining subscribers.
AI Inbox Summary
An AI inbox summary is an AI-generated digest that condenses unread email — often highlighting news, actions and senders — changing how clearly your marketing email reaches and engages subscribers.
ARPU (Average Revenue Per User)
ARPU (Average Revenue Per User) is a metric that measures the average revenue generated per email subscriber over a specific period, used to evaluate list value and campaign effectiveness.
Attention Rate
Attention rate is the percentage of email opens that last longer than 5 seconds, distinguishing genuine reads from passive opens, preview-pane views, or Apple MPP auto-loads.
Average Order Value in Email
Average order value in email is the average amount spent per transaction from recipients who clicked through from an email campaign.
Behavioral Segmentation
Behavioral segmentation is the practice of grouping subscribers based on their actions, such as opens, clicks, purchases, browsing and engagement patterns.
Frequently Asked Questions
Good practice here means handling Custom Event Tracking in Email in a way that is relevant, timely, and honest for your audience. Custom event tracking captures subscriber actions beyond standard email opens and clicks — such as video plays, form submissions, survey responses and scroll depth — giving marketers deeper behavioural insight. Done well, it improves engagement and builds trust; done poorly, it creates friction that costs you results.
Because it touches the parts of email that drive outcomes: relevance, trust, and delivery. Small improvements compound, while repeated mistakes quietly erode the health of your programme.
The most common problems are treating Custom Event Tracking in Email as a one-off task, ignoring what the data says, and copying competitors without testing. All three lead to effort that does not translate into better results.
Compare the metrics it should influence — engagement, conversions, and deliverability — before and after you make changes. Trends over time matter far more than any single send.
It supports the same goal as the rest of your email programme: the right message to the right person at the right time. Aligned with segmentation and automation, it reinforces everything else rather than competing with it.