Apple today previewed a new Safari feature called Privacy Preserving Ad Click Attribution that it says will allow advertisers to measure the effectiveness of their ad campaigns on the web without compromising user privacy.

safari mac mojave
In a blog post, WebKit engineer John Wilander explains that ad click attribution has traditionally been done through the use of cookies and so-called "tracking pixels," allowing both the advertiser and the website where the ad was placed to know when someone has clicked on an ad and later purchased something.

Wilander says the traditional method of ad click attribution has no practical limit on data, allowing for full cross-site tracking of users using cookies. "We believe this is privacy invasive and thus we are obliged to prevent such ad click attribution from happening in Safari and WebKit," he wrote.

Thus, Apple has proposed a modern solution that it says doesn't allow for cross-site tracking of users but does provide a means of measuring the effectiveness of online ads. The feature is built into the browser itself and runs on-device, meaning that the browser vendor does not see any of the ad data.

Here is Apple's summary of its privacy considerations for the feature:

  • Only links served on first-party pages should be able to store ad click attribution data.

  • Neither the website where the ad click happens nor the website where the conversion happens should be able to see whether ad click data has been stored, has been matched, or is scheduled for reporting.

  • Ad clicks should only be stored for a limited time, such as a week.

  • The entropy of both ad campaign ID and conversion data needs to be restricted to a point where this data cannot be repurposed for cross-site tracking of users. We propose six bits each for these two pieces of data, or values between 0 and 63.

  • Ad click attribution requests should be delayed randomly between 24 to 48 hours. This makes sure that a conversion that happens shortly after an ad click will not allow for speculative cross-site profiling of the user. The randomness in the delay makes sure the request does not in itself reveal when during the day the conversion happened.

  • The browser should not guarantee any specific order in which multiple ad click attribution requests are sent, since the order itself could be abused to increase the entropy and allow for cross-site tracking of users.

  • The browser should use an ephemeral session aka Private or Incognito Mode to make ad click attribution requests.

  • The browser should not use or accept any credentials such as cookies, client certificates, or Basic Authentication in ad click attribution requests or responses.

  • The browser should offer a way to turn ad click attribution on and off. We intend to have the default setting to be on to encourage websites to move to this technology and abandon general cross-site tracking.

  • The browser should not enable ad click attribution in Private/Incognito Mode.

Privacy Preserving Ad Click Attribution is available as an experimental feature in Safari Technology Preview 82 and later. To turn on the feature, enable the Develop menu and navigate to the Experimental Features submenu.

Apple says the feature will be turned on for web developers later this year. The company has also recommended it as a web standard to the W3C.

Top Rated Comments

BigBoy2018 Avatar
33 months ago
This could be a nice compromise between letting advertisers survive in the brutal www environment while also keeping users safe.

Personally I dont use ad blockers, I just dont click on the ads.

Then theres websites that will have an ad pop up over their content (CNN is a big offender). I just avoid those sites completely if at all possible.

P.S. and no, I don't have anything against CNN, except I hate the ads they allow on their site.
Score: 5 Votes (Like | Disagree)
now i see it Avatar
33 months ago
nice improvement, but does anyone really click on ads these days or even see them anymore now that there's ad blockers?
Score: 4 Votes (Like | Disagree)
SBlue1 Avatar
33 months ago
I use ad blockers, not because I hate ads as I know websites need to make money too. But because of the tracking. So anything Apple does in this direction is welcome.
Score: 4 Votes (Like | Disagree)
szw-mapple fan Avatar
33 months ago
nice improvement, but does anyone really click on ads these days or even see them anymore now that there's ad blockers?
It's no longer so much about clicking the ads anymore, although it's still important. With fingerprinting and cross-site tracking, advertisers can find out your purchase behaviour and ad effectiveness without you even clicking on the ad.
Score: 3 Votes (Like | Disagree)
weup togo Avatar
32 months ago
The paranoia runs deep with you. Im sure many spies are spending many hours a day studying your fascinating life
No, I just run my own local DNS, and see everything coming & going. Don't ascribe your technical ineptitude to everyone else.
Score: 2 Votes (Like | Disagree)
KazKam Avatar
33 months ago
Is this a serious question? How did you think Google and Facebook make there billions? Of course people click on ads. All the time. In fact, a study shows that 65% of clicks on Google Search results pages are click on ads while only 35% of clicks are on the organic results. And this number has been increasing over time.

https://www.bluecorona.com/blog/pay-per-click-statistics
I'd argue that's only because of Google's "dark" placement tactics, disguising ads as the top few search results. Users think they're clicking on legitimate search results, not placed/promoted ads.
Score: 2 Votes (Like | Disagree)

Popular Stories

macbook pro 13 inch banner

Apple Planning Five New Macs for 2022, Including Entry-Level MacBook Pro Refresh

Sunday December 5, 2021 7:55 am PST by
Apple is working on five new Macs for launch in 2022, including a new version of the entry-level MacBook Pro, according to Bloomberg's Mark Gurman. In the latest edition of his "Power On" newsletter, Gurman said that he expects Apple to launch five new Macs in 2022, including: A high-end iMac with Apple silicon to sit above the 24-inch iMac in the lineup A significant MacBook Air...
apple watch series 7 aluminum colors

2022 Apple Watch Lineup Rumored to Include New Apple Watch SE and 'Rugged' Model for Sports

Sunday December 5, 2021 8:22 am PST by
Apple is planning an entire revamp of its Apple Watch lineup for 2022, including an update to the Apple Watch SE and a new Apple Watch with a rugged design aimed at sports athletes, according to respected Bloomberg journalist Mark Gurman. Writing in the latest installment of his Power On newsletter, Gurman said that for 2022, alongside the Apple Watch Series 8, Apple is planning an update to ...
airtag in hand

Apple AirTag Linked to Increasing Number of Car Thefts, Canadian Police Report

Friday December 3, 2021 7:10 am PST by
Apple's AirTags are being used in an increasing number of targeted car thefts in Canada, according to local police. Outlined in a news release from York Regional Police, investigators have identified a new method being used by thieves to track down and steal high-end vehicles that takes advantage of the AirTag's location tracking capabilities. While the method of stealing the cars is largely ...
1x 1

Apple CEO Tim Cook 'Secretly' Signed $275 Billion Deal With China in 2016

Tuesday December 7, 2021 6:49 am PST by
Apple CEO Tim Cook "secretly" signed an agreement worth more than $275 billion with Chinese officials, promising that Apple would help to develop China's economy and technological capabilities, The Information reports. In an extensive paywalled report based on interviews and purported internal Apple documents, The Information revealed that Tim Cook personally forged a five-year agreement...
ipad air arrive feature

iPad Pro With Wireless Charging, iPad Air 5, and iPad 10 Reported to Debut in 2022

Sunday December 5, 2021 8:54 am PST by
Apple is preparing to update three of its iPad models in 2022, including the entry-level iPad, iPad Air, and iPad Pro, according to Bloomberg's Mark Gurman. In his latest "Power On" newsletter, Gurman reiterated Apple's plans to release a new iPad Pro in 2022, featuring a new design and wireless charging, and clarified the company's intention to release new versions of the entry-level iPad...
2021 MBP SD Card Error Feature

Some SD Cards Not Working Properly With 2021 14 and 16-Inch MacBook Pros

Monday December 6, 2021 2:02 pm PST by
The SD card reader slot on the new 14 and 16-inch MacBook Pro models is not functioning as expected with some SD cards, according to multiple reports on the MacRumors forums. In a long complaint thread, MacRumors readers have detailed the issues that they're having with some SD cards, and there seems to be little consistency between reports and affected SD cards. Some SD cards crash and...
airpods pro blue holiday 3

Deals: AirPods Pro With MagSafe Available for $169.99 and Christmas Delivery on Amazon ($79 Off) [Update: Expired]

Monday December 6, 2021 6:03 am PST by
Amazon today has Apple's AirPods Pro with MagSafe Charging Case for $169.99 and delivery before Christmas Day, down from an original price of $249.00. This is $10 off from the rock bottom $159.99 price tag we tracked on Black Friday and Cyber Monday, and still a great deal for anyone shopping this holiday season. Note: MacRumors is an affiliate partner with Amazon. When you click a link and...
life360 app

Tile Buyer Life360 Selling Precise Location Data on Millions of Users

Monday December 6, 2021 1:05 pm PST by
Location tracking service Life360 has been selling the precise location data of tens of millions of its users, according to a new report shared by The Markup. Life360 bills itself as a "family safety platform" app that is meant to allow family members to keep tabs on one another with tracking software that's installed on smartphones, and there are both Android and iPhone apps. The...