“I think you should drop the ‘How’ in the headline, as it is not addressed in the text.”

OK. Maybe this chart will help:

Click back and forth between iOS (AAPL) and Android (GOOGL) and you’ll see that the average selling price (ASP) of an iOS device has held more or less steady over the past five years while Android’s ASPs have halved.

Subscribe to Data Sheet, Fortune’s daily newsletter on the business of technology.

Back in September, market researchers at IDC predicted that smartphone prices would drop 4.6% per year for the next four years. But last quarter, with iPhone unit sales flat and their first-ever decline just three months away, iPhone ASPs actually increased, from $687 to $691.

Faced with a choice between protecting iPhone market shares and iPhone profit margins, Tim Cook stuck with profits.

For more on Apple, watch:

UPDATE: Asymco‘s Horace Dediu begs to differ. “Common misconception,” he tweeted Monday morning. “Apple is not concerned with keeping profits. It’s concerned with prices. Within the price is perception. Apple chooses deliberately to ‘own’ a price point and will never move from it. For 30 years the ASP of a Mac hardly changed. Same with iPod and same for iPhone.”