For example, advertisers can use a method called fingerprinting. 2 is where things also get slightly complicated.Īd-tech companies already have many ways to follow us beyond Apple’s device identifier. The second is that we communicate to the app developer that, broadly speaking, we don’t want our information to be tracked and shared with anyone in any way. The first is that Apple disables the app from using an Apple device identifier, a random string of letters and numbers that is assigned to our iPhones and is used to track our activities across apps and websites. When we select “Ask App Not to Track,” two things happen. Now, when you open some apps, you will be greeted with a pop-up window: “Allow to track your activity across other companies’ apps and websites?” You can choose “Ask App Not to Track” or “Allow.” When you opened other apps working with the same ad-tech firm, those apps were able to identify you and serve you ads for Brand X’s blender.Īpple’s new privacy feature is intended to let you decide whether you want that to happen. Those trackers looked at information on your device to pinpoint you. Here’s what happened: The shopping app hired an ad-tech company that embedded trackers inside the app. Later, ads for that blender start showing up in other mobile apps, like Facebook and Instagram. You look at a blender from Brand X, then close the app. Let’s say you use a shopping app to browse for a blender. It’s important to understand how tracking works inside apps.