Microsoft plans to drop cookies, embrace cross-device tracking tools

Microsoft(s msft) plans to replaces “cookies,” the long time method online firms use to gain data about users, in favor of new technology that will allow it to identify people as they move from device to device in an increasingly mobile world.

The decision, reported by AdWeek, comes weeks after news that Google(s goog) is likewise planning to move away from third party cookies, which collect information by dropping bits of code onto people’s browsers.

Microsoft reportedly plans to rely instead on device-based permission systems, which would let it identify when the same user is present on a variety of platforms — for instance, the company could follow a person on Internet Explorer, X-Box and Windows Phone in order to serve them the same ad on each.

The companies have been tight-lipped about how exactly cross-device tracking works, but it appears to rely on a combination of user-granted permissions and external signals — such as WiFi or web browsing patterns — that predict when the same user is on different devices (the New York Times has a good explanation of those signals).

The decision to drop cookies is significant because it reflects a shift of power in which companies will have access to data about how users roam the internet. Until now, a wide array of marketing and data companies have relied on third-party cookies to track and target customers but, in the future, that power will largely reside with a handful of major portals — including Facebook(s fb), Google, Apple(s aapl) and Twitter — which will be the guardians of customer data.

The news also suggests that long-running and troubled do-not-track discussions, which focused on cookies and involved the ad industry, may have been a red herring by the online ad industry all along.