One technology that is gaining traction is an advertising framework called Unified ID 2.0, or UID 2.0, which was developed by the Trade Desk, an ad-technology company in Ventura, Calif.
Say, for example, you are shopping on a sneaker website using UID 2.0 when a prompt pops up and asks you to share your email address and agree to receive relevant advertising. Once you enter your email, UID 2.0 transforms it into a token composed of a string of digits and characters. That token travels with your email address when you use it to log in to a sports streaming app on your TV that uses UID 2.0. Advertisers can link the two accounts together based on the token, and they can target you with sneaker ads on the sports streaming app because they know you visited the sneaker website.
Since your email address is not revealed to the advertiser, UID 2.0 may be seen as a step up for consumers from traditional cookie-based tracking, which gives advertisers access to your detailed browsing history and personal information.
“Websites and apps are increasingly asking for email authentication in part because there needs to be a better way for publishers to monetize their content that’s more privacy-centric than cookies,” Ian Colley, the chief marketing officer of the Trade Desk, said in an email. “The internet is not free, after all.”
However, in an analysis, Mozilla, the nonprofit that makes the Firefox web browser, called UID 2.0 a “regression in privacy” because it enabled the type of tracking behavior that modern web browsers were designed to prevent.
There are simpler ways for websites and apps to track your web activity through your email address. An email could contain your first and last name, and assuming you’ve used it for some time, data brokers have already compiled a comprehensive profile on your interests based on your browsing activity. A website or an app can upload your email address into an ad broker’s database to match your identity with a profile containing enough insights to serve you targeted ads.
The bottom line is that if you’re wondering why you are continuing to see relevant ads despite the rise of privacy tools that combat digital tracking, it’s largely because you are still sharing your email address.
Source : https://www.nytimes.com/2023/01/25/technology/personaltech/email-address-digital-tracking.html