Supply Optimization Best Practices

Major DSPs and demand partners (such as TTD) continue to prioritize transparent, signal-rich inventory across their marketplaces. Publishers and intermediaries that provide complete and accurate signals are better positioned to:

• Improve win rate and share of voice

• Increase eligibility for premium demand

• Drive stronger CPMs and deal performance

• Maintain parity with peer supply paths

This guide outlines required and strongly encouraged signals, and what publishers and sellers should implement to maximize demand performance through Sovrn.

Required Signals

The following signals are mandatory for maintaining eligibility across key demand partners. Non-compliance may result in reduced bid density, exclusion from buying paths, or enforcement actions.

1. Ads.txt, App-Ads.txt & Inventory Partner Domain (IPD) Compliance

To align with IAB policies, publishers must:

• List all authorized Inventory Partner Domains (IPD) in their app-ads.txt file.

• Include the IPD when inventory is not directly owned, but is instead monetized on behalf of the publisher by an intermediary or third party.

• Ensure the App Store URL passed in the bid request matches the declared app.

2. Sellers.json & SupplyChain Object Compliance

IAB requires publishers to post a sellers.json file and to pass a complete IAB SupplyChain (schain) object in the bid request where applicable.

Publishers/Intermediaries must:

• Host a sellers.json file that includes seller ID, seller name, domain, and the correct seller_type field.

• Ensure bid requests include a complete SupplyChain (schain) object that traces all intermediaries back to the originating publisher.

3. Impression Expiration (imp.exp)

Publishers should pass accurate imp.exp values in bid requests to signal the expected time (in seconds) between bid request and ad impression rendering. Accurate expiration handling improves bid validity, reduces expired impressions, and increases auction efficiency.

Recommended imp.exp values by environment:

• Web – Banner: 5–15 minutes

• Web – Video: 15–30 minutes

• App – Display: up to 1 hour

• App – Video and CTV: up to 2 hours

Publishers must ensure their monetization stack supports impression expiration logic, particularly for delayed-render environments such as pre-fetched or cached ad placements.

4. Send Only Secure Traffic

The industry is shifting to exclusively support secure programmatic traffic. Some DSPs, including Amazon, will only accept secure bid requests from 23 March 2026. Non-compliant requests may be filtered after enforcement, which could directly impact monetization.

Publishers must:

• Ensure all bid requests are flagged as secure (imp.secure = 1).

• Verify that all creative assets and tracking URLs use HTTPS.

• Review any supply-side configurations that may still be sending non-secure traffic.

Strongly Encouraged Signals

The signals below are not strictly enforced but have a material impact on demand performance, CPM yield, and eligibility for premium buying strategies. Publishers who adopt these signals consistently outperform those who do not.

5. ID Provenance & Identity Transparency

Accurate identity signalling is critical for DSP trust and bidding logic. Publishers must:

• Preserve original match method (mm) values in Extended Identifiers (EIDs).

• Correctly identify the matcher — the entity that created the ID linkage.

• Ensure buyeruid comes from a real-time cookie sync.

• Ensure device.ifa comes from the OS-level advertising ID.

• Use atype and mm consistently and in alignment with the origin of the ID.

See the full IAB ID Provenance specification for implementation details.

6. Open Measurement SDK (OMSDK) Adoption

The Open Measurement SDK (OMSDK) enables standardized viewability and impression measurement across in-app environments. DV360 and other major buyers increasingly expect OMSDK signals for verification and measurement vendors.

Benefits of OMSDK adoption:

• Standardized impression and viewability measurement across buyers and vendors.

• Independent third-party verification, improving buyer confidence.

• Fraud mitigation and device authenticity validation.

• Privacy-safe implementation aligned with IAB standards.

7. Live Event Signalling & Deal Packaging

Passing rich content signals for live sports and event inventory qualifies publishers for TTD’s Live Events and Sports Marketplace, providing access to incremental live sports budgets, higher deal quality scores, and stronger price discovery and CPM performance.

Publishers should pass the following content signals:

• Content ID

• Genre

• Channel

• Title

If full content signalling is unavailable:

• Set up sport- or league-specific private deals.

• Ensure deals contain only live, in-game inventory to maintain quality scores.

8. Content Signals for CTV

Passing rich content metadata significantly improves contextual targeting, enables more accurate pacing across content categories, and drives stronger valuation in programmatic environments. Publishers are strongly encouraged to send the following content signals:

• Genre

• Series

• Season

• Episode

• Title

• Production quality

• Duration

• Livestream indicator

• Network

• Channel

• Content rating

• Language

• Content ID

See the full list of supported content signals in the TTD Content Signal Taxonomy.

9. Content Placement & Video Metadata

DSPs such as TTD apply specific classification rules to video inventory based on placement characteristics. Incorrectly labelled video can be downgraded in value or excluded from in-stream demand entirely. Publishers must ensure video metadata accurately reflects the player environment.

Key placement and classification rules:

• In-stream video must be unmuted at start to qualify as true in-stream.

• If the video player can be scrolled out of view, or is not the primary content on the page, it may not be classified as in-stream by buyers, even if labelled as such.

• Out-stream and in-banner video should be declared accurately to avoid inventory misclassification.

• Autoplay behaviour, player size, and mute status should be consistently reflected in the bid request.

Recommended signals to pass for video:

• placement — distinguishes in-stream, in-banner, in-article, interstitial.

• plcmt — the OpenRTB 2.6 field replacing placement; pass both for compatibility.

• playbackmethod — e.g., auto-play sound on, auto-play sound off, click-to-play.

• startdelay — indicate whether pre-roll, mid-roll, or post-roll.

• skip and skipafter — declare whether the ad is skippable and when.

10. Identity & Addressability Adoption Benchmarks

High adoption of industry-standard identifiers materially impacts demand. Publishers should target the following benchmarks:

• GPID (Global Placement ID): Adoption should be as close to 100% as possible. Low GPID coverage often correlates with lower bid density compared to alternate supply paths.

• TDID (Trade Desk ID): Low TDID coverage may reduce addressable demand within TTD environments.

• UID2 (Unified ID 2.0): Publishers passing UID2 through some SSPs but not consistently across all paths may see fragmented performance.

• Beyond the identifiers listed above, publishers are encouraged to adopt any additional industry-standard IDs (such as RampID, ID5, EUID, or Publisher Provided Identifiers).
  The broader the ID coverage across supply paths, the greater the addressable demand and monetization potential

11. SKAdNetwork IDs

SKAdNetwork is Apple’s privacy-safe attribution framework for iOS. Since Apple restricted access to the IDFA via App Tracking Transparency (ATT), SKAdNetwork is the mechanism through which ad networks and DSPs can measure which ads led to app installs — without relying on user-level tracking.

Including Sovrn’s SKAdNetwork IDs in your app’s info.plist file is expected to improve spending from DSPs on your iOS inventory.

To implement:

• Add Sovrn’s SKAdNetwork IDs to your app’s info.plist file. The full list is available here: Sovrn SKAdNetwork ID List

• For full implementation guidance, refer to Apple’s official SKAdNetwork documentation.

Need Help?

If you have questions about any of the signals or configurations listed in this guide, or would like a review of your current setup, please contact your Sovrn account manager or contact our Support team.