Amazon Publisher Services / APS

Overview

Amazon Publisher Services (APS), built on the Transparent Ad Marketplace (TAM), is Amazon's header bidding solution for web publishers. It enables publishers to solicit bids from multiple demand sources simultaneously before calling their primary ad server, maximizing ad revenue. APS appears on publisher websites as part of the ad serving infrastructure, running pre-bid auctions in the user's browser.

What This Script Does

APS loads its header bidding library from c.amazon-adsystem.com/aax2/apstag.js. This script executes before the publisher's primary ad server call (typically Google Ad Manager) to run a parallel auction among Amazon's demand partners.

The APS tag performs the following operations on each page load:

1. Bid request — Sends auction parameters (ad slot sizes, page URL, publisher ID) to Amazon's bidding servers at aax.amazon-adsystem.com
2. User identification — Sets and reads cookies to identify the user across page views for frequency capping and bid optimization
3. Bid response — Receives bid prices and creative references from winning demand partners
4. Key-value passing — Injects winning bid data as key-values into the publisher's ad server request, allowing Amazon demand to compete in the final auction

Cookies set by APS include:

• ad-id — Amazon advertising identifier; 270-day expiry; used for cross-site user identification within Amazon's ad ecosystem
• ad-privacy — user's ad privacy preference state; 1,825-day expiry
• Auction-specific cookies for bid deduplication and frequency management

Network requests during the bidding process transmit the user's IP address, page context, ad slot information, and Amazon advertising identifiers to Amazon's servers. These requests also participate in real-time bidding protocols that share bid stream data with Amazon's demand partners.

APS integrates with Amazon's broader advertising data, meaning bid optimization benefits from Amazon's consumer purchase and browsing data. The header bidding auction happens on every page load, regardless of whether the user interacts with any ad.

Consent & Compliance

APS is classified as marketing. It is an advertising technology platform whose sole purpose is monetizing page views through programmatic ad auctions. It provides no functional benefit to the user.

Under the GDPR, APS requires explicit consent before execution. The header bidding process involves transmitting personal data (IP address, advertising identifiers, browsing context) to multiple demand partners in real time. This constitutes processing for advertising purposes under Article 6(1)(a). The involvement of multiple data controllers (Amazon and its demand partners) adds complexity to the consent and transparency requirements.

Under the ePrivacy Directive, the advertising cookies set by APS (particularly the 270-day ad-id cookie) require prior consent under Article 5(3). These cookies are not necessary for any user-requested service — they exist to identify users for ad targeting and frequency capping.

Under CCPA/CPRA, APS header bidding constitutes sharing (and potentially selling) personal information for advertising. The real-time bidding process broadcasts user data to multiple demand partners, each of which receives personal information for ad targeting. Publishers must disclose this data sharing and honor opt-out and GPC signals.

Should You Block This Without Consent?

Yes. Amazon Publisher Services runs programmatic ad auctions that share user data with multiple advertising demand partners on every page load. It sets long-lived tracking cookies and transmits personal data in real-time bidding requests. APS must not execute until the user has granted marketing consent.