Ad Platform Ecosystem Overview

Purpose

This document provides a compact introduction to the key participants and the basic flow of a modern ad platform ecosystem.

Key Takeaways

• Ad platforms connect demand-side participants and supply-side participants.
• Publishers provide inventory, while advertisers allocate budget to reach audiences.
• DSPs, SSPs, and exchanges automate and optimize this transaction flow.

One-Page View

Draft Structure

1. Why ad platforms exist

• Publishers need to monetize inventory.
• Advertisers need to reach relevant audiences efficiently.
• Platforms automate matching, bidding, and delivery at scale.

2. Core participants

Participant	Primary role
Advertiser / Agency	Campaign planning and budget execution
DSP	Automated buying and bidding
SSP	Supply monetization and yield optimization
Ad Exchange	Transaction layer connecting demand and supply
Publisher	Media owner providing ad inventory

3. Basic transaction flow

1. A user visits publisher inventory.
2. An ad request is triggered.
3. The supply-side platform exposes the opportunity to demand-side buyers.
4. A winning ad is selected and rendered.
5. Delivery and event logs are collected.

Out of Scope

• OpenRTB object structure
• ads.txt and app-ads.txt details
• Tracking, verification, and reconciliation details

Next Documents

• Roles of Publisher, SSP, DSP, and Exchange
• Ad Request vs Bid Request