CPI Explained: What Counts as an “Install”?
While “install” sounds straightforward, CPI programs often define it precisely. Some advertisers pay for a simple store install, while others require a quality install—for example, an install plus first open, account creation, tutorial completion, or a minimum session length. These extra requirements exist because mobile acquisition can be vulnerable to low-quality traffic and incentivized behavior.
As a result, evaluating CPI programs is less about the payout amount alone and more about the approval criteria, traffic restrictions, and whether the advertiser is optimizing for genuine users who will remain active.
What You’ll Learn
- Common CPI offer types and requirements
- How CPI tracking and attribution works
- Install quality, fraud prevention, and approval rules
- Key CPI metrics: eCPI, approval rate, and retention
- CPI vs CPA vs CPS: differences and best use cases
- How we review CPI affiliate programs
- How affiliates optimize CPI campaigns
- CPI FAQ + SEO schema
Common CPI Offer Types (And What They Require)
CPI offers vary from simple installs to multi-step “install + event” requirements. The more qualification steps included, the higher the payout is likely to be—because the advertiser is paying for more valuable users, not just downloads.
| CPI Type | Conversion Requirement | Most Common In | What Affiliates Should Watch |
|---|---|---|---|
| Basic CPI | Install from app store (sometimes no extra steps) | Utilities, broad consumer apps | Higher rejection risk if traffic quality is inconsistent |
| CPI + First Open | Install + first launch (open the app) | Most mobile offers | Attribution window, device targeting, SDK tracking accuracy |
| CPI + Registration | Install + create an account | Finance, marketplaces, social apps | Friction, verification requirements, compliant messaging |
| CPI + In-App Event | Install + complete event (tutorial, level, purchase intent) | Games, subscription apps | Event definition, time-to-event, quality filters |
| Incentivized (Restricted) | Install via rewards (only if allowed) | Selective networks/offers | Strict rules; often prohibited or heavily filtered |
How CPI Tracking and Attribution Works
CPI tracking is typically handled through mobile measurement partners (MMPs) or integrated tracking SDKs. Attribution determines which affiliate (or marketing channel) receives credit for the install, and attribution rules can differ by program.
- Affiliate sends a user through a tracked link.
- User lands in the app store (or a pre-lander, depending on program setup).
- User installs the app and opens it (if required).
- Tracking SDK/MMP attributes the install to the click.
- Install is recorded as pending until validated.
- Approved installs become payable commissions.
- Click attribution window (how long after click installs count)
- View-through attribution (if any, and whether it applies)
- Device/OS targeting (iOS vs Android restrictions)
- Geo restrictions (countries/regions supported)
- Re-attribution rules (new users only vs re-installs)
Install Quality, Fraud Prevention, and Why Approvals Matter
Mobile acquisition is heavily monitored for quality because installs can be generated through low-intent clicks, bots, device farms, or aggressive incentive tactics. For that reason, many CPI programs apply quality filters before approving commissions.
- New user only (no previous installs on the device/account)
- Minimum engagement (first open, session length, in-app event)
- Fraud signals (abnormal click-to-install time, device patterns, IP anomalies)
- Traffic compliance (prohibited sources, misleading creatives, incent restrictions)
Key Metrics for CPI Profitability
CPI performance is typically evaluated using both payout metrics and user quality metrics. A program can offer a high payout but still underperform if approvals are weak or if restrictions prevent scale.
| Metric | What It Means | Why It Matters for CPI | Reviewer Tip |
|---|---|---|---|
| CPI Payout | Fixed amount per approved install | Defines revenue per validated conversion | Compare within the same geo + OS mix |
| Approval Rate | % of tracked installs that become payable | Often the biggest driver of real earnings | Look for transparent rules and stable reporting |
| eCPI (Effective CPI) | Real earnings per tracked install after rejects | More realistic than headline CPI | Calculate: payout × approval rate |
| CTIT (Click-to-Install Time) | Time between click and install | Quality signal; extreme patterns can trigger fraud flags | Avoid forced flows; match intent and expectations |
| D1/D7 Retention | % of users active after day 1 / day 7 | Shows whether traffic produces real users | High retention often supports better rates and higher caps |
| Caps | Install limits by day/week/month | Limits scaling potential | Check if caps are negotiable for quality traffic |
CPI vs CPA vs CPS: What’s the Difference?
CPI is typically treated as a subtype of CPA because an install is a specific “action.” The main difference is that CPI focuses on mobile acquisition and often uses app measurement and SDK attribution. CPS requires a purchase.
| Model | Payout Trigger | Typical Environment | Most Common Risk Factor | Best Use Case |
|---|---|---|---|---|
| CPI | Approved install (sometimes + first open/event) | Mobile apps | Quality filters + fraud prevention + OS/geo restrictions | Publishers with mobile-first traffic and intent-matched funnels |
| CPA | Approved action (signup/trial/lead/etc.) | Web + app | Validation rules + compliance | Lead gen, trials, acquisition funnels |
| CPS | Approved purchase | eCommerce + subscriptions | Conversion rate + refunds/returns | Buyer-intent traffic and strong purchase influence |
How Affiliates Directory Reviews CPI Affiliate Programs
CPI programs are only as good as their tracking reliability and approval transparency. In reviews, we focus on whether affiliates can predict outcomes and scale responsibly without unexpected rejection patterns.
Our CPI Review Checklist
- ✓Install definition
Is it install-only, install + open, or install + event? We document the exact requirement. - ✓Tracking & attribution
Attribution windows, re-install rules, OS targeting, and reporting consistency. - ✓Traffic rules
Allowed channels, incent policy, creative guidelines, and compliance restrictions. - ✓Approval transparency
Clear rejection reasons, stable approval rates, and actionable reporting. - ✓Caps & scaling
Hard vs soft caps, and whether quality traffic can unlock higher limits or better payouts. - ✓Payout reliability
Hold period, payout schedule, thresholds, and partner support responsiveness.
How Affiliates Can Optimize CPI Performance
Successful CPI campaigns focus on intent matching and clean user journeys. The goal is to send users who actually want the app—reducing fraud flags, increasing retention, and improving approval stability.
Optimization levers that commonly improve CPI results
- Pre-qualify users: explain what the app does and set expectations to reduce quick uninstalls and low engagement.
- Use mobile-first placements: prioritize audiences browsing on the same device they will install from.
- Match geo + OS targeting: send only eligible users to avoid rejects.
- Avoid prohibited incentive tactics: incent traffic is often restricted or heavily filtered.
- Measure install-to-event: if the offer requires registration or event completion, optimize that step—not just the click.
FAQ: CPI (Cost Per Install) Affiliate Marketing
QIs CPI the same as CPA?
CPI is commonly considered a subtype of CPA because an install is a defined “action.” CPI focuses specifically on mobile app installs and typically uses app measurement and SDK attribution.
QWhy do CPI installs get rejected?
Installs may be rejected due to duplicate installs, re-installs, failed first-open requirements, suspicious traffic patterns, prohibited sources, geo/OS mismatches, or not meeting “quality install” criteria defined by the advertiser.
QWhat is eCPI?
eCPI (effective CPI) is the real earnings per tracked install after accounting for approvals and rejections. A simple way to estimate is: headline CPI × approval rate.
QDo CPI offers usually pay for iOS and Android equally?
Not always. Payouts and availability can vary by OS and country. Programs may offer different CPI rates for iOS vs Android depending on user value, conversion behavior, and advertiser demand.
QWhat traffic sources work best for CPI?
Mobile-first traffic sources generally perform best—such as mobile SEO, mobile content placements, compliant email (when allowed), and paid acquisition channels that can target eligible devices and geos. The strongest results typically come from intent-matched funnels that attract genuine app users.
Browse CPI Affiliate Programs (Reviewed)
Explore affiliate programs by commission model, including CPI app install offers with clear install definitions, transparent approval rules, and reliable tracking—reviewed to help you choose programs that match your traffic strategy.
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