Apple's AirTag Relies on a Feature No Competitor Can Match: One Billion IPhones

Users can attach Apple's newest gadget, AirTag, to valuables like keys or a backpack, and locate where it is on a live map inside Apple's built-in Find My software when it's lost. AirTag's most important differentiating feature isn't the technology inside the $29 coin-sized stainless steel gadget. It's other people's...