Apple’s privacy changes are poised to boost its ad products

The difference could eventually give Apple’s small but growing ad business an edge over rivals, ad executives and app makers say.

Apple’s latest operating system for iPhones has set off a firestorm in the ad industry and beyond by letting users decide whether to let apps track them for advertising purposes—changes that mean companies may soon have less data about who sees their ads. Apps on Apple’s iOS platform must ask users’ permission to track them for advertising purposes.

When targeting users who have opted out of tracking, advertisers who buy ads through third-party platforms will have to wait three days for insights on their campaigns and will only receive aggregate information,