{"id":8252,"date":"2026-11-04T08:19:00","date_gmt":"2026-11-04T01:19:00","guid":{"rendered":"https:\/\/adtek.agency\/?p=8252"},"modified":"2026-11-03T22:58:49","modified_gmt":"2026-11-03T15:58:49","slug":"what-is-cpi-cost-per-install","status":"publish","type":"post","link":"https:\/\/adtek.agency\/en\/what-is-cpi-cost-per-install\/","title":{"rendered":"What is CPI in app marketing? Cost per install formula, benchmarks and how to lower it"},"content":{"rendered":"

“What’s a good CPI?” is the question app clients ask me most, usually right after asking what CPI is. I tend to answer with another question: what is one install worth to your app? Until you have that number, a CPI of VND 5,000 or VND 20,000 says nothing about profit, and the max-CPI-from-LTV worksheet further down gets you there.<\/p>\n

In user acquisition<\/a> for apps, CPI (cost per install) is the average ad spend you pay for one install. Spend VND 30 million, measure 6,000 installs from your ads, and your CPI is VND 5,000. Don’t confuse it with CPI the consumer price index from the economic news.<\/p>\n

What is CPI in app marketing?<\/h2>\n

CPI = Ad spend \/ Installs from ads<\/strong><\/p>\n

“Spend” covers only what you pay the ad channel. An “install” is a first app open recorded by a mobile measurement partner (MMP) such as AppsFlyer or Adjust, not a download on the App Store or Google Play. Someone who downloads the app but never opens it does not count yet.<\/p>\n

Crediting each install to the right ad is called mobile attribution<\/a>. On Android it is fairly accurate. On iOS, when a user declines tracking through ATT<\/a>, the app cannot read the IDFA<\/a>, and installs are reported through SKAdNetwork<\/a> in aggregated form and with a delay. iOS CPI therefore always carries some error; how to read it is covered in our article on iOS app ad measurement<\/a>.<\/p>\n

CPI has two meanings. The first is a pricing model: you pay only when an install happens. Apple Ads Basic charges per install up to a maximum price you choose, while Apple Ads Advanced charges per tap (Apple Ads Help<\/a>). The second is a reporting metric: Meta or Google charge per impression or per click, and the spend is then converted into a cost per install.<\/p>\n

\"Apple
Apple states it plainly: Advanced is cost per tap, Basic is cost per install. Screenshot of the Compare Apple Ads solutions page, ads.apple.com, November 2026; pricing sections of both plans cropped and combined by Adtek.<\/figcaption><\/figure>\n

Cost per install vs CPA and eCPI<\/h2>\n\n\n\n\n\n\n\n\n
Metric<\/th>\nFormula<\/th>\nCommon trap<\/th>\n<\/tr>\n<\/thead>\n
CPI (cost per install)<\/td>\nSpend \/ installs from ads<\/td>\nSays nothing about whether the people who installed stay or buy<\/td>\n<\/tr>\n
eCPI (effective CPI)<\/td>\nTotal actual spend \/ total actual installs<\/td>\nAd platforms and MMPs count installs differently, so the two eCPI figures usually disagree<\/td>\n<\/tr>\n
Blended CPI<\/td>\nTotal spend \/ (paid installs + organic installs)<\/td>\nOrganic installs pull the number down and hide a paid channel that is losing money<\/td>\n<\/tr>\n
CPA (cost per action)<\/td>\nSpend \/ number of people who take action X after installing<\/td>\nPick an action too deep in the funnel and there is little data, so the algorithm learns slowly<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

According to AppsFlyer, CPI in the strict sense is a price agreed in advance for each install, while eCPI is the price you actually pay. Their example: $10,000 that brings in 5,000 installs gives an eCPI of $2 (AppsFlyer Glossary<\/a>). The “cost per install” figure in Meta or Google is really eCPI. In reports, separate organic installs<\/a> from blended CPI so they do not carry the paid channels.<\/p>\n

CPA goes one step further. Google App campaigns let you choose Target CPI (installs), Target CPA (in-app actions) or Target ROAS<\/a> (value). Google’s example: a budget of $100 a day with a Target CPI of $2 means you are aiming for about 50 installs a day (Google Ads Help<\/a>).<\/p>\n

\"Google
Google’s original Target CPI example: a $100 daily budget at a $2 target cost per install aims for about 50 installs a day. Screenshot of the About bidding in App campaigns page, support.google.com, November 2026.<\/figcaption><\/figure>\n

What makes CPI go up or down<\/h2>\n

On channels that charge per impression, CPI splits into two parts:<\/p>\n

CPI = CPM<\/a> \/ IPM<\/strong><\/p>\n

IPM (installs per mille) is the number of installs per 1,000 impressions. With a CPM of VND 50,000 and an IPM of 5, CPI is VND 10,000. Keep the CPM, push IPM up to 8, and CPI falls to VND 6,250. Each factor below works on one of those two parts.<\/p>\n