Apple's Cut From App Sales Reached $4.5 Billion in 2014 - NYTimes.com

Later in the article: "App Annie, an analytics firm that tracks mobile app sales, said that in the third quarter of 2014, Apple’s App Store revenue was 60 percent higher than revenue generated from Google Play."

"Apple continues to make billions of dollars from mobile apps sold in its App Store. The company said on Thursday that in 2014, billings from app sales rose 50 percent from the previous year, which results in roughly $15 billion in revenue for app developers and a $4.5 billion cut for Apple."

Apple's Cut From App Sales Reached $4.5 Billion in 2014 - NYTimes.com