‎When you browse the web, an increasing number of sites and apps are asking for a piece of basic information that you probably hand over without hesitation: your email address.‎

‎This may seem harmless, but when you enter your email, you’re sharing more than that. I hope this column, which includes some tasks, will prompt you to think twice before handing over your email address.‎

‎First, it helps to know why companies want email addresses. For advertisers, web publishers, and app makers, your email isn’t just important for contacting you. It serves as a digital bread piece for companies to link your activity across sites and apps to offer your respective ads.‎

‎If it all sounds familiar, it’s because of it.‎

‎For decades, the digital advertising industry relied on invisible trackers installed within websites and apps to follow our activities and then offer us targeted ads. Over the past few years, the system has undergone massive changes, including Apple’s launch of a software feature in 2021 that allows iPhone users to stop tracking apps and Google’s decision to stop websites from using cookies in its Chrome browser until 2024.‎

‎Advertisers, web publishers, and app makers now try to track people from other sources — and an easy way is to ask for an email address.‎

‎Imagine if an employee at a brick and mortar shop asked for your name before you entered. An email address may appear even more, as it can be linked to other data, including where you went to school, the structure and model of the car you drive, and your race.‎

‎”I can take your email address and search for data that you don’t even know you gave to a brand,” said Michael Prem, chief executive of Minneapolis-based advertising firm Modern Impact. “The amount of data we have as consumers is really shocking.‎

‎Advertising technology is constantly evolving, so when you enter an email address it helps to understand what you’re sharing. From there, you can decide what to do.‎

‎Your email address has become a powerful piece of data.‎

‎For many years, the digital advertising industry has set up a profile about you on sites visited on the web. Information about you was collected in secret ways, including cookies mentioned above and invisible trackers installed inside apps. Now that more companies are stopping the use of these methods, new techniques for targeting ads have emerged.‎

‎One technology that is gaining attention is an advertising framework called Unified ID 2.0, or UID 2.0, developed by TradeDesk, an ad technology company in Ventura, California.‎

‎For example, you’re shopping on a shoe website using UID 2.0 when a prompt comes up and asks you to agree to share your email address and receive relevant ads. Once you enter your email, UID 2.0 converts it into a token containing a string of numbers and letters. This token travels with your email address when you use it to log into a sports streaming app on your TV that uses UID 2.0. Advertisers can link both accounts together on tokens, and they can target you with shoe ads on the sports streaming app because they know you’ve visited the Sneaker website.‎

‎Since your email address isn’t displayed to the advertiser, UID 2.0 can be seen as a step for users from traditional cookie bread tracking, which gives advertisers access to your detailed browsing history and personal information.‎

‎”Websites and apps are increasingly demanding email authentication because publishers should have a better way to monetize their content that focuses more on privacy than cookies,” Ian Cooley, Chief Marketing Officer of TradeDesk, said in an email. “The internet isn’t free, after all.”‎

‎However, in one analysis, Mozilla, a non-profit organization that makes Firefox web browsers, called UID 2.0 ‎‎a “privacy retreat”‎‎ because it enabled the type of tracking behavior that was designed to deter modern web browsers.‎

‎There are easy ways for websites and apps to track your web activity through your email address. An email may include your first and last name, and assuming you’ve used it for some time, data brokers have already set up a comprehensive profile on your interests on your browsing activity. A website or app can upload your email address to the ad broker’s data BR to match your identity with a profile that has enough insight to offer you targeted ads.‎

‎In summary, if you’re wondering why you continue to see relevant ads despite the rise of privacy tools that combat digital tracking, it’s largely because you’re still sharing your email address.‎

‎So what to do?‎

‎There are various options for targeting you at your email address to limit the ability of advertising companies:‎

• ‎Create a group of email addresses. ‎‎Each time a site or app asks for your email, you can create a unique address to log in to, such as, for example, netflixbrianchen@gmail.com for movie-related apps and services. This will make it difficult for edtech companies to set up a profile BRD on your email handle. And if you receive spam mail to a specific account, it will tell you which company is sharing your data with marketers. This is an extreme approach, as it takes time to manage many email addresses and their passwords.‎

• ‎Use email masking tools. ‎‎ Apple and Mozilla offer tools that automatically create email aliases to log in to an app or site. Emails sent to Arafat are forwarded to your original email address. Apple’s HideMy email tool, which is part of its iCloud+ subscription service that costs 99 cents monthly, will make Arafat, but using it will make it more difficult to log in to accounts from a non-Apple device. ‎‎Mozilla’s Firefox Relay‎‎ will produce five email aliases at no cost. In addition, the program charges 99 cents a month for additional aliases.‎

• ‎When possible, get out. ‎‎ For sites that use the UID 2.0 framework to target ads, ‎‎you can choose‎‎ by entering your email address on https://transparentadvertising.org. (Not all sites that collect your email address are using UID 2.0.)‎

‎You can’t do anything either. If you enjoy receiving relevant ads and don’t have privacy concerns, you can accept that sharing some information about yourself is part of a transaction to receive content on the Internet.‎

‎I try to be cautious but moderate. I combine four email accounts dedicated to my core interests – food, travel, fitness and movies. I’ll use a movie-related email address, for example, when I’m logging into a site to buy movie tickets or stream videos. That way, these sites and apps will know about my movie preferences, but they won’t know everything about me.‎