build a reddit ads customer list custom audience from hashed identifiers

domain: ads-api.reddit.com/docs · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗

Steps

  1. Hash customer identifiers client-side (email as EMAIL_SHA256, mobile advertising ID as MAID_SHA256) before upload, since the API only accepts hashed values.
  2. Create a custom audience via the Ads API specifying action_type and column_order matching your hashed fields.
  3. Submit the user_data array in batches via the API for larger lists rather than the Ads Manager UI upload.
  4. Wait for processing (up to 24 hours, or several days for LiveRamp-based lists) before targeting the audience.
  5. Ensure the list meets Reddit's minimum match threshold (roughly 1,000 records, lower for LiveRamp-sourced lists).

Known gotchas

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