The Apple App Store generated over half a trillion dollars of sales in 2019 alone, a study has found. Conducted by the Analysis Group, the figure includes US$45 billion worth of in-app advertising and US$61 billion of digital goods and services.
https://www.notebookcheck.net/The-Apple-App-Store-generated-over-half-a-trillion-dollars-in-sales-in-2019.476774.0.html