Sharethrough

Overview

Sharethrough is a native advertising supply-side platform (SSP) headquartered in Chicago. It connects digital publishers with programmatic demand for in-feed and native ad placements — ad formats designed to match the look, feel, and function of the surrounding editorial content (in-feed articles, content recommendations, in-article slots). Sharethrough was acquired by Equativ (formerly Smart AdServer) in 2023, creating one of the larger independent SSPs in Europe and North America. Sharethrough's publisher tag participates in header bidding auctions via Prebid.js and direct integrations, serving demand from major DSPs including DV360, The Trade Desk, and Xandr.

What This Script Does

Script Files and Domains

The Sharethrough publisher tag loads from native.sharethrough.com/assets/sfp.js or via a Prebid.js adapter (sharethrough bidder). Additional resources load from sharethrough.com, btlr.sharethrough.com (bidder endpoint), and cdn.sharethrough.com. Ad creative assets for native placements are served from Sharethrough's CDN. User sync pixels fire to partner DSP domains during the consent-enabled ID sync process.

Cookies Set

• stx_user_id — Sharethrough's primary cross-site user identifier. Persistent, 30-day expiry. Set on sharethrough.com. Used to identify the browser across Sharethrough's publisher network for frequency capping and audience segmentation.
• stx_stv — Sharethrough visitor cookie tracking visit recency and frequency on the current publisher site.
• rlas3 — Retargeting audience segment cookie (set via Sharethrough's data partnership with LiveRamp).

Header Bidding Auction Flow

1. Prebid.js calls the Sharethrough adapter on page load, passing the publisher's ad slot configuration (placement ID, ad dimensions, content metadata).
2. Sharethrough's btlr.sharethrough.com/prebid endpoint receives the bid request containing: page URL, referrer, floor price, user ID (if available), and publisher-defined targeting parameters.
3. The bidder evaluates available demand (direct deals + open auction) and returns a bid response within the timeout window.
4. If Sharethrough wins the auction, the ad creative (native JSON object: headline, body, callToAction, thumbnailUrl, advertiserName, brandLogoUrl) is rendered by the publisher's native template.

Viewability and Brand Safety

Sharethrough's script integrates with IAS (Integral Ad Science) or MOAT for viewability measurement. The script fires MRC-compliant viewability events when 50% of the native ad is in-viewport for 1 second (display standard) or 2 continuous seconds (native standard).

User ID Sync

Sharethrough participates in cross-DSP cookie syncing via btlr.sharethrough.com/user-sync. During auction setup, the tag fires sync pixels to partner platforms (The Trade Desk's match.adsrvr.org, Amazon's aax.amazon-adsystem.com, Google's cm.g.doubleclick.net), passing Sharethrough's user ID in exchange for partner IDs. This enables cross-platform audience targeting for retargeting campaigns.

Seller Defined Audiences (SDA)

Sharethrough supports IAB Tech Lab's Seller Defined Audiences standard, allowing publishers to pass first-party audience signals (IAB content categories, contextual segments) into bid requests without exposing individual user identifiers.

Consent & Compliance

Category: Marketing

Sharethrough is a registered IAB TCF 2.2 vendor (Vendor ID 80). TCF purposes exercised: Purpose 1 (Store/access information on device), Purpose 2 (Select basic ads), Purpose 3 (Create personalised ads profile), Purpose 4 (Select personalised ads), Purpose 5 (Create personalised content profile), Purpose 7 (Measure ad performance), Purpose 10 (Develop and improve products). Special Feature 1 (precise geolocation) is declared as opt-in.

Under GDPR, all Sharethrough tracking operations require a valid TCF consent signal (Purpose 1 + relevant purposes). Without consent, no cookies should be set and bid requests should not contain personal data. Sharethrough's tag respects the TCF consent string passed by the CMP.

Under CCPA, the data shared with DSP partners during cookie syncing constitutes sharing personal information. The "Do Not Sell or Share" opt-out must suppress user ID syncing and targeted bid requests for California residents.

Sharethrough is registered under the EU-US Data Privacy Framework.

Should You Block This Without Consent?

Yes. Sharethrough is a programmatic advertising SSP with no functional value for site visitors. It sets persistent tracking cookies, syncs user identifiers across DSP partners, and serves targeted native ad placements. Block until marketing consent is obtained.