Summary

You may notice that Pixel unique metrics (such as New Visitors, Unique Visitors, Add to Cart, or Email Signups) appear higher when viewed at the Channel, Campaign, or Ad Set level than when viewed at the Ads level. This is expected behavior and is caused by how Pixel data is calculated and aggregated above the Ads level.

Pixel uniqueness is calculated at the Ads level. When Ads are grouped into Ad Sets, Campaigns, or Channels, totals are calculated by summing Ads without deduplicating users across Ads, which can result in higher totals at grouped levels.

Why This Happens

1. Ads Are the Lowest Level Where Pixel Uniqueness Is Calculated Independently
   At the Ads level, each Ad calculates its own unique users or actions (for example, New Visitors). A user is counted once per Ad.

2. Higher-Level Views Are Built by Summing Ads
   When Ads are grouped into Ad Sets, Campaigns, or Channels, totals are calculated by adding together the underlying Ads. These rollups do not deduplicate users across multiple Ads within the same grouping.

3. Users Can Be Counted More Than Once Above Ads
   If a person interacts with multiple Ads in the same Campaign or Channel, they may be counted once per Ad. This can cause grouped totals to be higher than the Ads-level view, even though the number of actual people did not increase.

Example Scenario

Consider the following example:

1. A user clicks on Ad A and visits the site for the first time.
2. Later, the same user clicks on Ad B from the same campaign within the same channel, and visits the site again.

In this case:

• Ad A reports 1 New Visitor.
• Ad B reports 1 New Visitor.
• When viewed at the Campaign or Channel level, the total is calculated by summing Ads.

Outcome:
The Campaign or Channel view shows 2 New Visitors, even though only one unique person visited the site.

How This Affects Reporting

• This behavior appears only above the Ads level (Ad Sets, Campaigns, Channels, All Channels).
• It affects unique-based Pixel metrics, including:
  • New Visitors
  • Unique Visitors
  • Add to Cart
  • Email Signups
• Differences are typically small but become more noticeable when users interact with multiple Ads.

How to Interpret the Data Correctly

1. Use Ads as the Baseline for Unique Metrics
   Ads are the lowest level where Pixel uniqueness is calculated independently. Higher levels represent aggregations of Ads.

2. Avoid Expecting Exact Matches Across Levels
   Channel-, Campaign-, and Ad Set–level totals are not deduplicated across Ads and should not be expected to exactly match Ads-level totals.

3. Focus on Trends Rather Than Exact Counts
   Grouped Pixel metrics are best used to understand relative performance and directional trends, rather than exact counts of individual people.

This behavior reflects a tradeoff in how Pixel data is aggregated: it enables flexible reporting across Ads, Campaigns, and Channels, but unique-based Pixel metrics may appear higher when viewed above the Ads level.