Cookies, in the context of the Internet, are small, sometimes encrypted text files, placed by websites in your browser’s directory, and retrieved next time you visit the site or load another page on the site. These cookies can be from the site, or from third parties such as ad networks.
What are cookies used for?
On e-commerce sites, cookies also store your shopping cart contents and quick checkout options.
Similar to TV commercials paying for most broadcast content, ads pay for the majority of the online content we freely access. Cookies help advertisers format ads on your computer; improve ad cost efficiency; attribute user engagement; and customize offers based on your browsing and search history. Given that ads are an established fact of online life, if you’ve just searched for lawn mower reviews, wouldn’t you rather see potentially useful ads for lawnmowers or fertilizer, rather than ads for, say, female hygiene products?
What challenges do cookies face in the mobile environment?
On mobile, whether phones or tablets, cookies try to do the same things they do on your desktop or laptop computer. However, where on your computer cookies inhabit your browser(s), in mobile they also need to operate in your various native applications (more commonly known as apps).
This sets up a distinct challenge for cookies.
On your computer, whether your operating system is Windows, MacOS, or Linux, and whether you use Safari, Firefox, Internet Explorer, Chrome, or any other browser, your cookies can count on your browser using hypertext markup language, or http. This provides a uniform environment, and since most users use the same browser on the same computer most of the time, a cookie can see nearly all your online activities.
In mobile, not only are there dozens of different types of devices, running different operating systems, with different mobile web browsers, each with its own rules, those browsers play in different “sandboxes” from the native apps on the same device. Further, each of those apps plays in a different sandbox from each other. Finally, while you probably only use one computer, you may have a work cell phone, a personal cell phone, a tablet, one or more gaming consoles, and possibly a car-based Internet-connected device.
While reports of the demise of cookies on mobile are likely a bit premature, tracking your online behavior across all those mobile devices, networks, and apps does pose a mostly insuperable challenge for the humble cookie. As a result, advertising vendors face increasingly tough questions from their clients about targeting prospective customers, and accurately calculating conversion rates on mobile devices.
Another result is that users’ privacy preferences, such as tracking opt-out, entered on one app are unlikely to be respected on other apps or on the mobile web browser, or vice versa, simply because the ad networks don’t recognize the different instances of visitor interactions as belonging to the same person.