· 4 min read

15 Ad-Tech Terms Every Mobile Game Developer Should Know

Ad mediation? CPM? Waterfalling? All key terms that are used throughout the industry, but what do they really mean?

Ad-tech is starting to get all the more significant in the mobile games industry, so it’s important that you’re schooled up. To give you a hand, we’ve put together some of the top key terms you need to be familiar with, in alphabetical order (feel free to bookmark this page, by the way, as we’ll likely keep this updated with new terms we come across).

Ad exchange

Online marketplaces where publishers, advertisers, agencies, ad networks, DSPs and SSPs can buy and sell ad inventory from each other.

Ad fraud 

Ad fraud is when an advert says it’s been seen, but a human has never actually looked at the ad. And the reason why it’s fraud is because there’s still a cost attached to this impression.

Ad inventory

The total amount of space a publisher has available on their site or app for adverts at any one time.

Ad network

A company that sells publishers’ ad inventory to advertisers, making their money by taking a cut of ad revenue.

DSP (Demand-side platform)

This stands for demand-side platform. It’s software that lets advertisers buy ad inventory from ad exchanges, and manage advertising campaigns. A DSP accesses data from lots of different sources, then analyses and bids for impressions as they come up for sale. It can connect to multiple ad exchanges.

CPM (Cost per mille) 

This stands for ‘cost per mille’ which translates as ‘cost per thousand impressions’ (‘mīlle’ being Latin for ‘thousand’, fact fans). It’s basically the amount an advertiser pays a website per one thousand visitors who see their ads.

eCPM (effective cost per mille) 

This is pretty much the same as CPM. However, the main difference here is the formula used. CPM is normally used to work out the cost of a campaign, whereas eCPM is used to determine the value of it. (Still sounds a bit complicated? Mobvista actually explains this pretty well. See their definition here.)


See ‘Waterfalling’.


A single view of an ad by one person. Online publishers offer their ad inventory as available impressions.

Header bidding 

Almost the exact opposite of waterfalling, header bidding means that impressions are all auctioned off at the same time. We’re actually putting together a handy post that discusses this topic in more depth. We’ll add a link here once it’s posted. 

Mediation platform

These give publishers centralized access to multiple ad networks.

Programmatic advertising

A system that automates the processes and transactions involved in buying and placing ads on websites or apps. It usually does this through an exchange or DSP. Programmatic advertising makes it possible to buy and place ads in less than a second.

RTB (Real-time bidding) 

This stands for ‘real-time bidding’ and is pretty much what it says on the tin – an automated auction process for buying individual ad impressions on websites, apps, games, etc in real time.

SSP (Supply-side platform)

This is a software system that lets publishers offer their available ad inventory for sale to ad exchanges and demand-side platforms (DSP)s.


This is a romantic name for a not-very-romantic process used by publishers to sell ad inventory. Publishers create a list of ad networks they want to use and rank them in order of preference (which often means the one with the highest rates will be at the top). Then, when they have an impression to sell, a mediation platform tries to sell it to the ad network that’s top of the list. If that one doesn’t want it, it goes to the next one, then the next (and so on), until someone buys it (hence the name). It’s also called, equally romantically, daisy-chaining.

Think we’ve missed anything? Let us know, and we’ll add it to our list. Just to let you know, we’ll soon be releasing more content to cover this space (our next post tackles header bidding). But for the moment, you can learn more from these posts: