Email Advertising vs Web Advertising
Email advertising behaves differently from traditional web advertising due to how email clients load content and how email providers handle images and tracking. These differences can impact how certain metrics appear in reporting.
Understanding these behaviors will help advertisers interpret campaign performance more accurately.
📧 How Email Ads Are Delivered
Unlike web advertising, where ads are rendered dynamically each time a page loads, email advertisements are delivered within a pre-sent message.
When a user opens an email, the email client loads the images contained in that message. These images may include advertisements served by our ad platform.
This means:
- Ads are loaded when the email is opened, not when the email is sent.
- Each email open can generate a new opportunity for an ad to be displayed.
Proxy Servers in Email
Many email providers route image requests through proxy servers.
Common examples include:
- Apple Mail Privacy Protection
- Gmail image proxy
- Yahoo Mail proxy
- Outlook image proxy
Proxy servers request images on behalf of the user before delivering them to the email client.
This behavior improves user privacy and security but can affect how advertising metrics appear.
📊 How Proxy Traffic Affects Reporting
Because proxy servers request images on behalf of users, certain metrics may behave differently compared to web advertising.
Impressions
Some email clients preload images when an email is opened. This can cause impressions to be recorded even if the user does not actively view every element within the email.
Impressions in email should be interpreted as potential exposure rather than confirmed visual engagement.
🗺️ Geographic Data
Proxy servers may mask the user’s precise location.
In most cases:
- Country-level location data is reliable.
- State or city-level data may be less accurate.
Advertisers targeting proxy traffic should generally rely on country-level targeting.
📱 Device Identification
Proxy servers may request content using different device signals than the user’s actual device.
For example, a mobile email client may retrieve images through a proxy server that appears as a desktop environment.
This is why reporting includes a Device / Proxy dimension that distinguishes between device types and proxy environments.
Email Engagement Happens Over Time
Email interactions do not always occur immediately after an email is sent.
Users may:
- Open emails hours after receiving them
- Reopen emails multiple times
- Click advertisements days after the initial send
Because of this behavior, campaign activity may continue well after the original email delivery.
Cached Ads and Delayed Clicks
When an email is opened, ad content may be cached for a period of time.
If a user reopens the same email later, the previously served advertisement may still appear.
Clicks on these cached ads can occur even when the campaign line is no longer actively serving impressions.
For this reason:
- Clicks may occur outside configured dayparting windows.
- Campaign reporting may include engagement from previously delivered impressions.
Comparing Email Metrics to Web Metrics
Some metrics behave differently in email compared to traditional web advertising.
| Metric | Email Advertising | Web Advertising |
|---|---|---|
| Impressions | Triggered when images load in the email | Triggered when ads render on a webpage |
| Click timing | Can occur long after email delivery | Usually occurs shortly after page load |
| Geo accuracy | May be affected by proxy servers | Typically based on user IP |
| Device signals | May reflect proxy environments | Usually reflects the user’s actual device |
Because of these differences, advertisers should focus on engagement and outcome metrics when evaluating performance.
Key metrics to monitor include:
- Clicks
- Conversions
- CPA
- ROAS
Best Practices for Email Campaign Analysis
When analyzing campaign performance:
- Focus on engagement metrics such as CTR and CVR
- Evaluate ROAS and CPA to measure efficiency
- Compare performance across device and proxy categories
- Monitor trends over time rather than single-day performance
Email advertising is best optimized through consistent monitoring and incremental improvements.
Summary
Email advertising offers a powerful way to reach engaged audiences within newsletters and other email content. However, the technical behavior of email clients and proxy servers can affect how campaign data appears.
By understanding these differences, advertisers can interpret reporting data more accurately and make better optimization decisions.
Updated about 1 month ago