Facebook Users Said No to Tracking. Now Advertisers are Panicking

When users get asked on iPhone devices if they’d like to be tracked, the vast majority say no. That’s worrying Facebook Inc.’s advertisers, who are losing access to some of their most valuable targeting data and have already seen a decrease in effectiveness of their ads.

The new prompt from Apple Inc., which arrived in an iOS software update to iPhones in early June, explicitly asks users of each app whether they are willing to be tracked across their internet activity. Most are saying no, according to Branch, which analyzes mobile app growth. People are giving apps permission to track their behavior just 25% of the time, Branch found, severing a data pipeline that has powered the targeted advertising industry for years.