Mobile & app · also called Mediation, mediation platform
Ad mediation
Ad mediation is software that lets app developers connect many ad networks and bidders through one SDK and chooses which network fills each ad request to maximise revenue.
An app developer wants the highest price for every ad slot, and no single network always pays most. A mediation platform plugs many demand sources into one integration and decides who serves each impression.
Traditionally, mediation worked as a waterfall: networks were ranked by historical average price, and each request was offered to them in order until one accepted. Modern platforms use in-app bidding, where networks bid in real time in a unified auction, often combined with remaining waterfall lines. Major platforms include AppLovin MAX, Google AdMob mediation and Unity LevelPlay.
Mediation is the in-app equivalent of header bidding plus an ad server. It raises questions familiar from the web: some mediation platforms also run their own ad networks, which creates potential conflicts of interest, and developers should understand auction rules and fees. Mediation data also helps spot problems, such as a network with high fill but low viewability, or suspicious discrepancies.
Think of it like this
Ad mediation is like an estate agent who shows your house to every interested buyer at once and accepts the best offer, rather than asking one buyer at a time.
An example
A casual-games studio in Poland moves from a 12-step waterfall to in-app bidding with eight networks through its mediation platform; average eCPM rises 20% and ad latency falls.
Related terms
In-app bidding
In-app bidding is a real-time auction inside mobile apps where multiple ad networks and buyers bid simultaneously for each ad impression, replacing the sequential mediation waterfall.
Waterfall (daisy-chaining)
A waterfall is an older way of selling ads in which an impression is offered to demand partners one at a time, in fixed priority order, until one fills it.
SDK (software development kit)
An SDK (software development kit) is a package of pre-built code developers add to apps to provide features, such as showing ads, measuring installs or analytics, without building them.
In-app advertising
In-app advertising is ads shown inside mobile apps, such as games, utilities and social apps, as opposed to ads on websites viewed in a mobile browser.
Unified auction
A unified auction is a single auction in which all demand sources, such as direct campaigns, header bidders and exchanges, compete for an impression under the same rules at the same time.
Sources: IAB Tech Lab OpenRTB