Digital marketing term
CPI
Average cost to get one app install from a campaign. You pay for the download, not the click, which is why acquisition teams treat it as the unit price.
Detailed explanation
Choose it when the goal is a store install—app ads, incentivized networks, or some video units sell this way. Web leads belong on CPL; purchases on CPA. Chasing the cheapest install invites fake devices and rewarded junk.
The trap is treating the download as success. If the app never opens, never registers, or is deleted overnight, the budget is gone. Creative must match the store listing; a wide net drops the rate and the quality together.
Read install cost next to first open, sign-up, and day-7 retention. Cheap installs with high uninstalls mean you cut the network or the promise. The decision is kept users, not install volume.
Frequently asked questions
- Is an install the same as an active user?
- No. The store records the install. Value shows up in opens, registration, and retention. CPI alone hides quality.
- What inflates the cost?
- Competition, incentivized traffic, and a weak store page. Fix the promise and targeting before you raise bids blindly.
Related terms
Internal links for the topic cluster — read these concepts together.
- CPACPA (Cost Per Action) is a pricing and performance model based on completed actions such as a sale or form submission.
- CPLWhat you pay for one defined lead: a form, trial request, or callback. Cheap clicks still get expensive when those forms are junk that sales cannot use.
- CPCCost per click: what you pay when someone clicks, not when the ad is only shown. The auction and Quality Score — or the platform equivalent — move that price as much as your bid does.
- ConversionThe defined action you wanted completed: a purchase, signup, download, or form. Traffic without that count means the campaign flew blind on its results.
- ROASROAS (Return on Ad Spend) is the revenue generated for every unit of advertising spend; it is used to measure profitability in performance marketing.
- Unique UserA person or device identity counted once in the reporting window; that same identity can still generate many visits. Clearing cookies or switching phones can split one human into two records.