Mobile & app · also called Mobile in-app ads
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.
Most mobile time is spent in apps, and many apps are free because they carry ads. In-app advertising covers the formats shown there: banners, interstitials, rewarded video, native ads and playables.
It runs on different plumbing from the web. Apps integrate an ad SDK from networks or a ad mediation platform, which requests ads, often through in-app bidding where multiple demand sources compete in real time. Devices are identified by mobile advertising IDs where available, and measurement uses the Open Measurement SDK and mobile measurement partners. Advertisers are often app developers themselves, running install campaigns.
In-app advertising has distinct risks. App spoofing misrepresents which app an ad ran in, hidden ads run while an app is in the background, and install fraud targets cost-per-install deals. app-ads.txt and sellers.json help verify sellers. Apple's App Tracking Transparency also reduced available identifiers on iOS, pushing more reliance on contextual signals and SKAdNetwork/AdAttributionKit.
Think of it like this
In-app advertising is like the adverts on the walls of an arcade: the games are free or cheap because the sponsors pay for the space.
An example
A puzzle game with 5 million daily players in Southeast Asia earns most of its revenue from rewarded video and interstitial ads served through a mediation SDK that runs in-app bidding among eight networks.
Related terms
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.
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.
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.
Rewarded video
Rewarded video is an opt-in ad format, mostly in mobile games, where users choose to watch a video ad in exchange for an in-app reward like extra lives or coins.
app-ads.txt
app-ads.txt is the version of ads.txt for mobile and CTV apps, a file on the app developer's website that lists which sellers are authorised to sell the app's ad inventory.
Sources: IAB Tech Lab Open Measurement SDK, IAB Tech Lab ads.txt and app-ads.txt