Digital marketing term
Ad Space
The placement where an ad sits, plus the inventory that slot can sell. A fixed unit, run of site, and run of network are not the same product.
Detailed explanation
Ad space is the publisher’s sellable slot: leaderboard, in-article, sidebar, app screen. Direct deals lock a unit; ROS runs anywhere eligible on the site; RON runs across a network. The same stock can also clear in an RTB auction.
The mistake is buying ‘above the fold’ and accepting refreshed, stacked, or off-screen units. Rotation splits delivery on a shared slot. A floating layer can show the brand and still wreck UX and viewability.
Put size, position, viewability, and share of voice in the contract. Compare CPM on inventory that actually stayed on screen. On the publisher side, unsold space is leftover revenue, not a branding win by default.
Frequently asked questions
- How is ROS different from a fixed unit?
- A fixed unit locks one placement. ROS may serve anywhere eligible on the site; you do not get a position guarantee.
- Why can cheap space cost more?
- Off-screen, refreshed, or bot-heavy inventory lowers CPM and also fails to deliver viewable impressions or conversions.
Related terms
Internal links for the topic cluster — read these concepts together.
- Display AdvertisingBanners, native units, and other visual formats on sites and apps. Unlike search text ads, they show up before someone has typed a query into the box.
- PublisherThe party that owns the content and the ad inventory: a site, app, or show. Advertisers buy the impressions; this side sells the space and the audience.
- AdSenseGoogle’s display network for publishers: it fills on-site slots and pays a share of clicks or impressions. It is not the same product as Google Ad Manager for larger inventory.
- ImpressionAn impression is a single instance of an online ad being displayed to a user.
- Run of NetworkAds that run across a network’s inventory without locking to a specific page: you skip site picks and the network fills what it can. CPM usually drops, and so does topical fit.
- Run of SiteAds that rotate across one site’s inventory without locking to a section or URL. The buy is wider than a homepage sponsorship and tighter than a network-wide run.