Run of Site (ROS)

An ad buy that runs anywhere across a single publisher's site rather than in specific sections, usually at a lower price.

By Brandon MinaCEO, BrandPilot AIUpdated November 2026

Short answer

Run of site (ROS) is an ad buy in which ads can appear anywhere across a single publisher's site rather than in specific sections or placements. Because the advertiser gives up control over exact placement, ROS inventory is usually priced lower than section-targeted buys and is often used to build broad reach efficiently.