What is an Ad Exchange?

An ad exchange is a digital marketplace where advertisers and publishers can buy and sell ad space in real-time through an automated bidding process known as real-time bidding (RTB). In an ad exchange, publishers make their ad inventory available to multiple buyers, while advertisers bid on these impressions, competing to show their ads to targeted audiences. This automated, data-driven process enables ads to be served almost instantly, allowing brands to reach relevant audiences across a wide range of websites, apps, and digital platforms.

Ad Network vs. Ad Exchange

While both ad networks and ad exchanges are platforms for buying and selling ad space, they differ significantly in function, transparency, and control.

Ad networks package and resell inventory to advertisers, offering ease of entry but less transparency and limited control over where ads appear. In contrast, ad exchanges operate as real-time marketplaces, allowing advertisers to bid on individual impressions with greater insight into pricing, placement, and audience targeting.

For advertisers who prioritize granular targeting, transparency, and performance-driven campaigns, ad exchanges are often the preferred choice. Ad networks, however, may appeal to those seeking simple, broad reach without the need for detailed placement control.