That bold pronouncement got me wondering whether Mr. Cook uses a different iPhone from every iPhone that Apple has ever sold me. On my iPhone, Google is right there in the search bar, by default. Microsoft’s Bing is built into Siri, and Facebook and Twitter beckon me from the sharing menu.

Image Credit... Stuart Goldenberg

If Apple really didn’t think that its customers should trade their data for free services, you’d guess that it would build its own ad-free web search engine for its devices. But Apple does not do so. Instead, it sells off the search bar to ad-supported search companies. Analysts at Goldman Sachs say that Apple’s current deal with Google is worth billions; at least indirectly, then, Apple benefits financially from Google’s ad-gotten gains.

And that’s not all. When I go to Apple’s App Store, I’m presented with a bevy of free apps that are supported either in whole or in part by ads. This vibrant marketplace works in Apple’s favor — the more free apps there are, the more useful the iPhone becomes. That dynamic explains why, in 2010, Apple created iAd, its own advertising network meant to foster the ad-supported app marketplace. IAd lets marketers target users of Apple’s devices based on their purchases from the iTunes store, purchases that Apple of course tracks by default. (You can use an ad-supported search engine like Google to find instructions for opting out.)

There’s nothing terribly wrong with any of this. Yes, there are downsides to the ad-supported tech industry, and, yes, privacy advocates and tech insiders like Mr. Cook should continue to push the entire industry to more stringently protect our data. But it would be insane to argue that we haven’t seen benefits in return for this data. Anyone who uses devices like the ones Apple makes can see that ad-driven businesses like Google, Facebook and Twitter have improved people’s lives in major ways.

Among other things, ad-supported services give us instant access to more information than was ever stored in the entirety of the world’s libraries just a few decades ago. They also create systems that allow for instant communication and organization between more than a billion people. They are helping to provide life-changing miniature computers, also known as phones, to people in developing nations for about $50 each. They’ve given us artificial-intelligence supercomputers that can instantly translate languages or recognize speech. And, indirectly, they’re creating upcoming wonders like self-driving cars and balloons that wire up the globe in Internet access.

Mr. Cook is fond of arguing that “when an online service is free, you’re not the customer; you’re the product.” That view is simplistic because it overlooks the economic logic of these services, especially the idea that many of them would never work without a business model like advertising. Services like social networks and search engines get substantially better as more people use them — which means that the more they cost to users, the worse they are. They work best when they’re free, and the best way to make them free is to pay for them with another business that depends on scale — and advertising is among the best such businesses.

Mr. Cook is right to promote Apple’s privacy policies. Apple places more restrictions on the use of data than other tech companies. This has been especially true recently after Apple moved to institute more rigorous security measures after an embarrassing hacking last fall in which female celebrities’ photos were stolen from their iCloud accounts.