In September of 2017 Apple released new changes to Safari with Apple iOS 11 called “Intelligent Tracking Prevention,” which will bring changes that  will have large effects on the ad tech industry and will create new winners and losers , according to an article published inForbes New Tech.

The iOS 11 changes will really help the big guys, are neutral to the small guys and significantly hurt the mid-size guys.

Today, all Safari browsers essentially block third-party cookies that are dropped by domains other than the domain of the URL to which the user has browsed. But the browsers reward first-party cookies with lots of privileges. This has been good for well-known sites, but also for large ad networks that get lots of clicks because a click gets routed through the ad network domain and becomes a first-party cookie.

IOS 11 will change the concept of a “first-party cookie.” The new first-party cookie comes with a ticking clock. In the first 24 hours, the cookie acts exactly like it used to – and can be used for retargeting. So, if you go to JetBlue Airways and search for a beach vacation, you can be retargeted for that beach vacation for exactly 24 hours. It is just like Jack Bauer  racing against the clock before the world explodes.

For the first 30 days, the new first-party cookie lets you login on-site so you don’t have the annoyance of re-entering your password if you go back to the site 15 days later.

If you have not gotten back to the site in 30 days, your first-party cookie expires.

The Losers

Traditional ad networks: Slightly negative impact. Because Safari has not enabled third-party cookies for a long time, many ad networks will not be affected by the iOS change because they were already unable to participate in the Safari economy. They might suffer a bit because this move will likely lower the price of Safari inventory and raise the price of Google Chrome and Internet Explorer inventory, both of which promote third-party cookies.

Large retargeters and demand-side platforms (DSPs): Very negative impact. This class of third-party ad networks received a lot of clicks, which resulted in first-party cookies for a large percentage of their users. Now the number of first-party cookies they have access to could decline by more than 98% in Safari. Expect forward-thinking companies in this category to come up with some innovative solutions to help them navigate this new world.

Publishers: Very negative impact. As mentioned, some of the largest high-dollar bidders of Safari inventory, including large retargeters and DSPs, will stop bidding on Safari. The average CPM price for Safari should decline significantly. Publishers, especially higher-end publishers that cater to wealthy iOS users, will be stuck with many low-dollar bidders, less relevant ads and potentially unhappy users who have to see even more annoying ads.

The Winners

Facebook and Amazon: Very positive impact. Not surprisingly, Facebook and Amazon are the big winners in this change. Most of their users come every day or at least every week. And even the mobile users click on links often, which, on Facebook, takes them to a browser. These companies will also be able to buy ad inventory on Safari at lower prices because many of the high-dollar bidders will go away.

Google: An initially negative impact that will be positive in the long term. Google’s long-term gain will have short-term pain. That’s because most of the off-property ads are in the “” domain and not “”. We should expect Google to merge these domains so that everything is under the “” domain – but that will take time to fully roll out. On the flip side, we should see more ad money flee people using Safari browsers, which means likely a bigger advertiser ecosystem on Android and Chrome.

In conclusion iOS 11 changes really help the big guys, are neutral to the small guys and significantly hurt the mid-size guys.

This question originally appeared on Quora – the place to gain and share knowledge, empowering people to learn from others and better understand the world.