Glossary/Adtech & Programmatic/Buy Side vs. Sell Side
Adtech & Programmatic
Buy Side vs. Sell Side
The buy side (advertisers, agencies, DSPs) purchases ad inventory; the sell side (publishers, SSPs, exchanges) offers and monetizes it.
By Brandon Mina·CEO, BrandPilot AI·Updated November 2026
Appears in Lesson 2 of Programmatic 101
Short answer
The buy side and sell side are the two halves of the advertising market. The buy side, including advertisers, agencies, and DSPs, purchases ad inventory to reach audiences. The sell side, including publishers, SSPs, and exchanges, offers and monetizes that inventory. Each side uses its own technology and pursues different goals around price and performance.