Publisher
In advertising, a publisher is the owner of a website, app, or media property that sells ad space to advertisers to monetize its audience.
A publisher is the owner of a website, app, newsletter, or other media property that sells advertising space on its content to earn revenue. In the ad ecosystem the publisher is the supply side, it provides the audience and the ad placements that advertisers want to reach.
How it works#
A publisher monetizes its audience by making inventory available for ads. It can sell directly to an advertiser, or, far more commonly today, connect to demand programmatically through an ad network, SSP, or exchange, which fills its slots with bidding advertisers in real time. Publishers are paid on the impressions or clicks they deliver, and they measure how well their inventory monetizes using metrics like RPM (revenue per thousand impressions).
Why it matters#
In native advertising, the publisher is where the recommendation widget or in-feed ad actually appears, so knowing which publishers carry an advertiser's ads reveals their site-targeting and supply choices. Publisher quality also drives brand-safety and performance: the same ad converts very differently on a premium news site versus a thin arbitrage page. OpenAdLibrary records the publisher site behind each captured ad, letting you see where advertisers place their spend.
Related terms: Advertiser, Ad Network, Ad Placement, and RPM.
