The feature will be on by default in Safari in a release later in 2019 and is available in a preview solution now. Apple hopes to make it a true web standard, and has submitted a proposal through the World Wide Web Consortium's web platform's incubator community group.
Advertisers may not be satisfied with the technology. Although it still lets them see how ads translate into more business, it will prevent them from tracking real-time habits. They wanted a harder time to decide when and where to run ads. Apple insists that this is an acceptable trade-off, though. The extra privacy can prevent people from taking more drastic measures to protect their privacy, such as disabling cookies and using ad blockers.