App Store Connect metric
App Store conversion rate
Apple's conversion rate is downloads and pre-orders divided by unique device impressions: what it means, and why third-party benchmarks often don't compare.
Definition
Total downloads and pre-orders divided by unique device impressions. A pre-order counts once, when it's made, not again when it downloads.
(Total downloads + pre-orders) ÷ unique device impressions
Where to find it
App Store Connect › Analytics › Acquisition
The common mistake
Downloads ÷ product page views gives a much higher number and is often reported as "conversion rate". Comparing your Apple rate with a benchmark built on page views makes your app look worse than it is.
What to use it for
Comparing store page changes over time and against Apple's peer group benchmarks, which use the same definition. Read it by source: Search and Browse convert very differently.