Cookies, those controversial electronic bookmarks that tell advertisers how consumers browse their sites, might not be controversial for much longer. That’s because in the move from computer interfaces to mobile commerce, cookies become obsolete. They even may start to appear quaint, compared with the sorts of tracking technologies advertisers are developing to locate customer through their smartphones and other devices, determine their collective behaviors, and target them with incredibly specific advertisements.

Cookies do not work with mobile apps. Instead, many apps automatically or with users’ permission gather extensive information about where the consumer is, what he or she is seeking, and how long he or she remains active. With this information, new technologies also can link users, according to their unique identifications, across various devices.

In particular, a new venture called Drawbridge (founded by a former employee of Google’s mobile advertising division) maintains partnerships with various advertising platforms and publishers, which create notifications of every visit a user makes to a website or app. These notifications in turn enter data analyses that rely on statistical modeling to determine which person is using which devices and link them together—as well as determine whether multiple users rely on the same device. Thus when a person downloads an app through her phone, then later visits a site that appeared in that app, the software enables advertisers to connect those devices as belonging to a single user. In turn, information from both devices gets integrated. The next day, if this user visits a travel site through her computer, she might receive an advertisement for rental cars through her phone. However, if her spouse visits a gaming site instead, Drawbridge knows that it is a different user and personalizes the advertising accordingly.

As these technologies and related software grow more sophisticated, mobile service providers are seeking to make sure users continue to agree to be tracked. Thus for example Verizon promised coupons to consumers who agreed to let it share information about their mobile browsing behaviors with advertisers, and AT&T simply announced that it had begun selling aggregated consumer data to advertisers.

Despite such announcements, most consumers appear to remain relatively unaware of the extent to which companies are following exactly what they do, every time their link to a website or mobile service. The National Security Administration also acknowledged that in 2010 and 2011, it gathered data about the locations of cellphones using data from cell towers. And no existing legislation prohibits third parties from collecting or sharing usage data.

Source: Claire Cain Miller and Somini Sengupta, “Selling Secrets of Phone Users to Advertisers,” The New York Times, October 5, 2013