Installs per mille (IPM): what IPM means in app and game ads

Short answer. In mobile app advertising, IPM means installs per mille: how many app installs an ad produces for every 1,000 impressions. It is installs times 1,000, divided by impressions, and it is the cleanest single number for whether a creative turns attention into installs.

(IPM also stands for integrated pest management in agriculture. This page is about the advertising metric.)

Definition

Unity's glossary defines IPM as "a metric that is used to track the number of app installs per thousand ad impressions," used "as part of a mobile advertising or user acquisition strategy which aims to buy new users for an app." Unlike CTR, which stops at the click, IPM measures the whole path from impression to install: the ad, the end card, the store page and the decision to download.

Formula

IPM = (installs x 1,000) / impressions

In Unity's words, IPM is "calculated by multiplying the number of campaign installs by 1000, and then dividing that number by the number of impressions."

IPM connects directly to cost. Since CPI is spend divided by installs and CPM is spend per thousand impressions, CPI = CPM / IPM. Double IPM at the same CPM and you halve CPI.

Worked example (illustration)

These are made-up round numbers. Creative A gets 200,000 impressions and 1,000 installs: IPM = 1,000 x 1,000 / 200,000 = 5. Creative B gets 200,000 impressions and 1,600 installs: IPM = 8. At a $20 CPM, A's CPI is $20 / 5 = $4.00 and B's is $20 / 8 = $2.50.

What a good or bad reading tells you

A rising IPM means more of the people who saw the ad installed. Unity notes a second effect: "Improved IPM has the added benefit of boosting eCPM, and ultimately the rank of the advertising campaign in advertising networks waterfalls. This in turn results in higher volumes of ad impressions and installs." In other words, a higher-IPM ad tends to be shown more, because it earns the network more per impression (see eCPM).

A falling IPM on an unchanged ad is a common sign of creative fatigue. A low IPM with a high CTR usually means the ad attracts clicks the store page does not convert.

We do not give an IPM benchmark. It varies by genre, country, platform and placement, and we have not found a dated, named source we would stand behind across those.

How it is used in app, game and brand advertising

Unity notes IPM is "often used as part of a mobile advertising or user acquisition strategy." In our view it is the most useful creative metric in game UA, because it isolates the creative's job from bid and budget. It is less used by commercial brands that optimise to purchases, but the same logic (conversions per thousand impressions) is how we compare creative for them too.

Common mistakes

1. Comparing IPM across placements. In our experience rewarded, interstitial and banner inventory behave very differently.
2. Reading IPM on small samples. A few hundred impressions cannot separate two ads.
3. Chasing IPM with a misleading ad. Installs that do not match the game hurt retention.
4. Ignoring the store page and end card, which sit inside the IPM path.

Flixr's view

Our view: IPM is the closest thing app advertising has to a pure creative score, and it is the number we try to move. Our own tool calls winners by what the networks keep funding rather than by what got clicks, and a high-IPM ad is usually one the network keeps funding. For where installs are won after the video, see our end cards guide and how to lower CPI on AppLovin.