How Google’s Ad Ecosystem Works

If a dog food company wants to advertise a new treat online, it hires a creative agency to design an ad. That ad goes to the digital-ad ecosystem, a bewildering array of buyer and seller platforms that manage ad-space inventory, auction off space, and track responses. Google is a major player almost every step of the way.

The ad is loaded onto a server, where it sits until the advertiser and publishers have agreed on price and placement. Google Campaign Manager competes with Innovid Inc. and Amazon.com Inc.’s Sizmek, among others.