SAN FRANCISCO — Smartphones know everything — where people go, what they search for, what they buy, what they do for fun, and when they go to bed.
Privacy advocates fear that consumers do not realize just how much of their private information is on their phones and how much is made vulnerable simply by downloading and using apps, searching the mobile Web or just walking around with a phone in your pocket.
And this new focus on tracking users through their devices and online habits comes against the backdrop of a spirited public debate on privacy and government surveillance.
On Wednesday, the National Security Agency confirmed it had collected data from cellphone towers in 2010 and 2011 to locate Americans’ cellphones, though it said it never used the information.
“People don’t understand tracking, whether it’s on the browser or mobile device, and don’t have any visibility into the practices going on,” said Jennifer King, who studies privacy at the University of California, Berkeley and has advised the Federal Trade Commission on mobile tracking. “Even as a tech professional, it’s often hard to disentangle what’s happening.”
Drawbridge is one of several startups that has figured out how to follow people without cookies, and to determine that a cellphone, work computer, home computer, and tablet belong to the same person, even if the devices are in no way connected. Before, logging onto a new device presented advertisers with a clean slate.
“We’re observing your behaviors and connecting your profile to mobile devices,” said Eric Rosenblum, chief operating officer at Drawbridge. But don’t call it tracking.
“Tracking is a dirty word,” he said.
Drawbridge, founded by a former Google data scientist, says it has matched 1.5 billion devices this way, allowing it to deliver mobile ads based on websites the person has visited on a computer. If you research a Hawaiian vacation on your work desktop, you could see a Hawaii ad that night on your personal cellphone.
For advertisers, intimate knowledge of users has long been the promise of mobile phones. But only now are numerous mobile advertising services that most people have never heard of — like Drawbridge, Flurry, Velti, and SessionM — exploiting that knowledge, largely based on monitoring the apps we use and the places we go. This makes it ever harder for mobile users to escape the gaze of private companies, whether they are insurance firms or shoemakers.
Ultimately, the tech giants, whose principal business is selling advertising, stand to gain. Advertisers using the new mobile tracking methods include Ford Motor, American Express, Fidelity, Expedia, Quiznos, and Groupon.
“In the old days of ad targeting, we give them a list of sites and we’d say, ‘Women 25 to 45,’ ” said David Katz, the former general manager of mobile at Groupon and now at Fanatics, the sports merchandise online retailer. “In the new age, we basically say, ‘Go get us users.’ ”
In those old days — just last year — digital advertisers relied mostly on cookies. But cookies do not attach to apps, which is why they do not work well on mobile phones and tablets. Cookies generally work on mobile browsers, but do not follow people from a phone browser to a computer browser. The iPhone’s mobile Safari browser blocks third-party cookies altogether.
Even on PCs, cookies have lost much of their usefulness to advertisers, largely because of cookie blockers.
Responding to this problem, the Interactive Advertising Bureau started a group to explore the future of the cookie and alternatives, calling current online advertising “a lose-lose-lose situation for advertisers, consumers, publishers, and platforms.” Most recently, Google considered creating an anonymous identifier tied to its Chrome browser that could help target ads based on user Web browsing history.
For many advertisers, cookies are becoming irrelevant anyway because they want to reach people on their mobile devices.