Auction Economics and Identity
The money and the matching. Understand why the industry moved to first-price auctions, how buyers shade bids and sellers counter with floors, how identity raises match rates and CPMs, and the accurate, current state of cookie deprecation and the Privacy Sandbox.
What do L1–L5 mean?depth, beginner → expert
Each module carries a depth band. A range like L3–L4 means it spans two.
- Foundations
- Vocabulary and the big picture. No prior ad-tech assumed.
- Practitioner
- The hands-on basics you use day to day.
- Intermediate
- Real configuration and the trade-offs behind it.
- Advanced
- Optimization, edge cases, and running at scale.
- Expert
- Architecture and deep specialization.
Prereqs: A3, B6
Objectives- Define second-price and first-price auctions.
- Explain the shift to first-price: header bidding broke the symmetry, and opaque soft floors plus last-look made second-price untrustworthy.
- Explain the consequences.
Key conceptsSecond-price auctionFirst-price auctionLast-look and soft floorsClearing priceRead the lesson →AssessmentCompute the clearing price under first- vs second-price for the same bid set.
DEBUGProposed auction-mechanics simulator.
Prereqs: D1
Objectives- Define bid shading and why sellers counter with dynamic floors.
- Reason about the shading-vs-floors arms race.
Key conceptsBid shadingDynamic floorsThe shading / floors arms raceRead the lesson →AssessmentExplain to a publisher why first-price CPMs fell and how a dynamic floor recovers some.
DEBUGProposed shading-vs-floor simulator.
Prereqs: D1, B8
Objectives- Define a floor.
- Configure the Price Floors module: hard-coded vs dynamic floors, the rules schema (ad unit / media type / size / device / first-party data), floorMin, and enforcement.
Key conceptsPrice floorHard-coded vs dynamic floorsThe floors rules schemafloorMin and enforcementRead the lesson →AssessmentAuthor a floors config with a size- and device-dimensioned schema, then explain what happens to a $0.30 bid against a $0.50 enforced floor.
PRACTICEProposed floors-rule editor.
DEBUGProposed "all bids rejected because the floor was mis-keyed" reproduction.
Prereqs: B8
Objectives- Explain why identity matters: match rate, then bid density, then CPM.
- Configure the User ID module and UID2 / EUID, ID5, and RampID.
- Understand how IDs pass into the bid stream (eids).
Key conceptsUser ID moduleUID2 / EUID, ID5, RampIDeids in the bid streamMatch rate drives bid density and CPMRead the lesson →AssessmentChoose an identity stack for a logged-in vs an anonymous-traffic publisher and wire a two-ID config.
PRACTICEProposed User ID composer.
DEBUGProposed "ID absent because consent withheld it" reproduction.
Prereqs: D4
Objectives- Tell the accurate, current narrative: Google announced third-party-cookie deprecation, repeatedly delayed it, in July 2024 said it would not force-deprecate, in April 2025 dropped the Chrome choice prompt, and in October 2025 wound down the Privacy Sandbox initiative, while Topics / Protected Audience continued in reduced form.
- Conclude that third-party cookies persist in Chrome for now, so identity diversification is a hedge, not an emergency.
- Place Safari ITP and Firefox ETP in context.
Key conceptsThird-party-cookie deprecation timelinePrivacy Sandbox (Topics, Protected Audience) wind-downSafari ITP and Firefox ETPIdentity diversification as a hedgeRead the lesson →AssessmentWrite a 200-word "where we actually are on cookies in 2026" brief.
ANALYZEProposed Safari vs Chrome match-rate simulation.
DEBUGProposed match-rate-under-cookie-loss reproduction.
Complete this track
Five questions drawn from this track. Get 4 right to mark the whole track done.
1.Why did header bidding move to first-price auctions?
2.Bid shading is used by…
3.A price floor is…
4.Identity solutions (shared IDs) primarily aim to…
5.The current state of cookie deprecation / the Privacy Sandbox is best described as…