What is CPI (Cost Per Install)?
Understanding CPI
Installers are not equal—optimize for quality (registration, purchase) once CPI is stable. Hook‑first creative and product visuals improve pre‑click intent and lower CPI. Store conversion and listing quality (screenshots, copy, reviews) drive post‑click install rate. Audience and geo choice can swing CPI dramatically. Align creative, targeting, and store assets to the same promise.
Balance delivery and quality by shifting optimization once volume stabilizes. Test creators, formats, and 9:16 native vertical aggressively for mobile. Keep event schemas consistent so downstream optimization can learn. Read CPI with retention and payback to ensure scaling installs makes economic sense. Exclude recent installers and cap frequency to avoid waste.
Why CPI (Cost Per Install) matters
CPI matters because it sets clear guardrails for user acquisition efficiency and determines which geos and placements are economically viable to scale. Lower CPI expands your addressable market by making more channels profitable, while monitoring CPI trends helps identify creative fatigue or competitive pressure. Pairing CPI with downstream quality metrics like retention and LTV ensures you're acquiring valuable users, not just cheap installs that churn immediately.
- Efficiency: Sets guardrails for user acquisition
- Scale: Lower CPI expands viable geos and placements
- Quality: Pair with downstream KPIs to avoid cheap, low-value installs
How to Calculate CPI
- Formula: CPI = Ad Spend ÷ Installs
- Track by platform/placement and by creative concept.
Meta Information
- Primary Keyword: CPI (Cost Per Install)
- Secondary Keywords: app install cost, cost per install formula
- Target Word Count: 800–1,000 words
- Meta Title: What is CPI? Cost Per Install Explained | Marpipe
- Meta Description: CPI measures what you pay per app install. Learn the formula, how creatives drive CPI, and when to optimize to downstream events.
- URL: marpipe.com/ad-glossary/cpi-cost-per-install
# What is CPI (Cost Per Install)?
CPI is the average cost to acquire an app install. It depends on creative clarity, store conversion, and auction competition.
Understanding CPI
Installers are not equal—optimize for quality (registration, purchase) once CPI is stable. Hook‑first creative and product visuals improve pre‑click intent and lower CPI. Store conversion and listing quality (screenshots, copy, reviews) drive post‑click install rate. Audience and geo choice can swing CPI dramatically. Align creative, targeting, and store assets to the same promise.
Balance delivery and quality by shifting optimization once volume stabilizes. Test creators, formats, and 9:16 native vertical aggressively for mobile. Keep event schemas consistent so downstream optimization can learn. Read CPI with retention and payback to ensure scaling installs makes economic sense. Exclude recent installers and cap frequency to avoid waste.
How to Calculate CPI
- Formula: CPI = Ad Spend ÷ Installs
- Track by platform/placement and by creative concept.
Why CPI (Cost Per Install) matters
CPI matters because it sets clear guardrails for user acquisition efficiency and determines which geos and placements are economically viable to scale. Lower CPI expands your addressable market by making more channels profitable, while monitoring CPI trends helps identify creative fatigue or competitive pressure. Pairing CPI with downstream quality metrics like retention and LTV ensures you're acquiring valuable users, not just cheap installs that churn immediately.
- Efficiency: Sets guardrails for user acquisition
- Scale: Lower CPI expands viable geos and placements
- Quality: Pair with downstream KPIs to avoid cheap, low-value installs
Best practices
- Lead with the core value prop in the first seconds.
- Use store badges and social proof where allowed.
- Match creative to store screenshots and description.
- Test 9:16 native vertical formats aggressively.
- Shift to value-based optimization once CPI is efficient.
How to Calculate CPI
- Formula: CPI = Ad Spend ÷ Installs
- Track by platform/placement and by creative concept.
Key Takeaways
- CPI (cost per install) is ad spend divided by app installs; it measures install efficiency.
- Lower CPI by improving creative relevance, targeting precision, and app store optimization.
- Track CPI alongside retention and LTV to ensure installs translate to value.
- Segment CPI by platform, audience, and creative to identify efficient acquisition paths.
