InsightsAudience Overlap

Audience Overlap

The Audience Overlap dashboard lets you compare two or more audiences to see shared membership. Understand how your segments intersect, plan deduplication strategies, design exclusion targeting, and analyze audience composition with visual overlap analysis.

What Audience Overlap Shows

When you select two or more audiences, SignalSmith evaluates their current membership and computes the intersection. The result shows:

  • How many members belong to multiple audiences — The overlap count and percentage
  • How many members are exclusive to each audience — Members in one audience but not the others
  • The degree of redundancy — Whether audiences are substantially duplicated or genuinely distinct

Overlap Visualization

Two-Audience Comparison

For a two-audience comparison, the dashboard displays a Venn diagram with three zones:

ZoneDescription
Audience A OnlyMembers who are in Audience A but not in Audience B
Audience B OnlyMembers who are in Audience B but not in Audience A
OverlapMembers who are in both Audience A and Audience B

Each zone shows both the absolute member count and the percentage relative to the total unique members across both audiences.

Multi-Audience Comparison

When comparing three or more audiences, the dashboard shows:

  • A set intersection table listing all combination groups with their member counts
  • Pairwise overlap percentages for every pair of selected audiences
  • A summary bar showing what fraction of total unique members appear in exactly 1, exactly 2, or 3+ audiences

Overlap Metrics

MetricFormulaDescription
Overlap Count|A ∩ B|Number of members in both audiences
Overlap Percentage (A)|A ∩ B| / |A| × 100Percentage of Audience A that overlaps with Audience B
Overlap Percentage (B)|A ∩ B| / |B| × 100Percentage of Audience B that overlaps with Audience A
Jaccard Similarity|A ∩ B| / |A ∪ B| × 100Normalized overlap metric independent of audience sizes
Exclusive to A|A| - |A ∩ B|Members only in Audience A
Exclusive to B|B| - |A ∩ B|Members only in Audience B
Total Unique|A ∪ B|Unique members across both audiences

How to Use Audience Overlap

Deduplication Planning

If you’re syncing multiple audiences to the same destination, overlap analysis helps you understand the actual incremental reach of each audience:

  1. Select the audiences that sync to the same destination
  2. Review the overlap — high overlap means you’re sending largely the same people via multiple syncs
  3. Consider consolidating overlapping audiences into a single audience to reduce sync volume and destination API costs

Example: “High-Value Customers” and “Repeat Buyers” may have 80% overlap. Instead of syncing both to your CRM, create a single “High-Value Repeat Buyers” audience or sync only the one that better matches your use case.

Exclusion Targeting

Use overlap analysis to build exclusion audiences for advertising:

  1. Compare your “Current Customers” audience with your “Prospecting” audience
  2. If there’s significant overlap, members who are already customers are seeing prospecting ads
  3. Create an audience sync for “Current Customers” as a suppression list in your ad platform
  4. The ad platform will exclude these members from prospecting campaigns, reducing wasted spend

Understanding Audience Composition

When designing a new audience, compare it against existing audiences to understand who you’re targeting:

  1. Create your new audience (e.g., “Holiday Campaign 2024”)
  2. Compare it against key reference audiences:
    • “All Active Customers” — What fraction of your active base is being targeted?
    • “Previous Holiday Campaign” — How different is this year’s targeting from last year?
    • “High-Value Customers” — Are you including your best customers?
  3. Adjust the new audience’s filter criteria based on the overlap insights

Funnel Analysis

Compare audiences that represent different stages of a customer journey to understand conversion flow:

Signed Up (10,000)
  → First Purchase (3,500) — 35% conversion from signup
    → Repeat Buyer (1,200) — 34% conversion from first purchase
      → VIP (300) — 25% conversion from repeat buyer

By checking the overlap at each stage, you can verify that later-stage audiences are proper subsets of earlier-stage audiences (which they should be if your filters are correctly nested).

Running an Overlap Analysis

  1. Navigate to Insights > Audience Overlap
  2. Click Select Audiences and choose two or more audiences to compare
  3. Click Analyze
  4. SignalSmith evaluates the current membership of each audience and computes the intersection
  5. Results are displayed immediately with the Venn diagram and metrics table

Note that overlap analysis evaluates audiences in real-time against your warehouse, so very large audiences may take a moment to compute. Results are not cached — each analysis reflects the current state of your data.

API Endpoint

GET /api/v1/insights/audience-overlap

Computes overlap between two or more audiences.

Query Parameters:

ParameterTypeDescription
audience_idsstringComma-separated list of audience IDs to compare (required, minimum 2)

Response Fields:

FieldTypeDescription
audiencesarrayArray of { audience_id, audience_name, member_count }
overlap_countintegerNumber of members in the intersection of all selected audiences
pairwisearrayArray of { audience_a, audience_b, overlap_count, overlap_pct_a, overlap_pct_b, jaccard }
exclusive_countsobjectMap of audience_id → exclusive member count
total_uniqueintegerTotal unique members across all selected audiences

Related Resources

Activation CoverageOverview