Stephanie Bauer Marshall, who serves as a director of marketing for Verizon Wireless, is confident that the mobile advertising ecosystem is in chaos today. And cross-device tracking technology helps brands and publishers to make sense of the chaos.

What is cross-device tracking?

This is a technology, which has myriads of ways to identify Internet users through different types of devices, including smartphones, tablets and desktop computers. The goal of any cross-device campaign is to know exactly that the person using the smartphone X is the same person who uses the laptop Y and the tablet Z, and then to allow the brands to implement retargeting according to the findings.

Why is it important?

Because reorientation to the mobile device is not possible without cross-device tracking. Retargeting allows the brand to identify the consumer on its website, and then show the advertisement to him elsewhere. For example, if a person browsed a page of Chuck Taylor on the site of Zappos, then tomorrow he can see the banner of Zappos when visiting Yahoo Finance.

So what's the problem?

It's quite easy to ensure retargeting on the desktop computers because of the presence of cookies - small test files that are created when a particular user visits a particular site. In the case of mobile devices, "cookies" do not work. Yes, they exist in a mobile app of Chrome from Google, but these files do not work in other countless applications used by consumers. This significantly complicates the process of tracking users across multiple devices. And given the runaway growth of the "population" of various gadgets, platforms, publishers and mobile operating systems, the problem becomes even more complex.

Is there a solution to this problem?

Tom Phillips, the general manager of marketing technologies department in the company Dstillery, believes that there are two ways of carrying out cross-device campaigns - "deterministic" and "probabilistic". In the first case, publishers ask their users to login on the sites using all the devices that they have. This method is used, for example, by Facebook and Twitter.

The probabilistic method is very inaccurate. For example, the companies Drawbridge and Tapad, which use it, collate information about the advertisements that have been shown on smartphones, tablets and desktop computers, and then use statistical models to find out who uses this or that device. This is a very complex process that requires just an incredible amount of data. Tapad collects monthly about 250 billion data points, including IP-addresses, types of devices, applications or Web browsers! Over time, the company gets a set of behavioral patterns that tell us about how consumers move from one device to another.

How accurate is probabilistic method?

As the name implies, the accuracy of this method is lame. But, despite this, it can give good results. Usually, companies use this method with an accuracy from 60 to 90 percent.

Why should I take all these difficulties?

Many believe that the inability to track users across multiple devices is the main reason that brands are not willing to spend money on mobile advertising. If a publisher can prove that the ad on a smartphone led to the subsequent buying on a desktop computer, brands'll change their attitude towards mobile advertising. Cross-device tracking is also an integral part of understanding of the differences in consumer behavior on mobile and stationary devices. And this is the basis of success.

Whether all companies are experiencing similar difficulties?

No. As mentioned above, on such platforms as Twitter and Facebook, users can log in the system with one profile that allows these companies to fairly accurately retarget the user using different devices. Google is the leader in this respect, which has several products that work both on desktop computers and mobile devices. And through each of the devices you can log in using your Gmail or Google Plus account. Perhaps, better hand of these companies will continue to grow, because they all operate their own ad networks, which allow them to track their target audience across devices and sites. That's why there is nothing surprising in the fact that Google, Facebook and Twitter dominate in mobile advertising market.

What about publishers?

Publishers, who were able to convince the users to create a profile on the website and sign up with it on different devices, have a similar advantage, too. However, few publishers can do it. Playing fantasy football on Yahoo, you need to create a profile and use it for both desktop and mobile applications that makes it possible to identify the user through a variety of devices. This is especially true for sites with paid access, which require their subscribers to create new accounts on different devices. However, for most publishers the best way for cross-device tracking is the partnership with high-tech advertising companies. This allows them to make assumptions that are based on knowledge of the real situation.