Roles of Publisher, SSP, DSP, and Exchange
Purpose
This document clarifies the roles of the core players that are frequently confused in ad platform discussions.
Key Takeaways
- Publishers provide the inventory where ads are shown.
- SSPs optimize monetization from the publisher side.
- Exchanges operate as a transaction layer between supply and demand.
- DSPs optimize media buying from the advertiser side.
- Advertisers define budget, targeting, and creative goals.
Relationship Diagram
Draft Structure
1. Publisher
- Provides ad slots and content context.
- Can be a website, mobile app, or CTV app.
2. SSP
- Optimizes monetization of publisher inventory.
- Can manage floors, routing, prioritization, auction outcomes, and log collection.
3. Exchange
- Acts as the transaction layer where demand and supply meet.
- In practice, exchange and SSP responsibilities may overlap.
4. DSP
- Evaluates bidding opportunities based on advertiser goals and targeting conditions.
- Determines whether to bid and how much to bid.
5. Advertiser
- Defines budget, campaign goals, and targeting conditions.
- Decides through the DSP which audiences and inventory to buy.
Common Misunderstandings
- An SSP is not the system that creates ad creatives.
- A DSP is not usually the runtime that renders the ad.
- An exchange is not always a completely separate business entity.