Dive Brief: 

• Because desktops' main data-tracking method — the cookie — doesn't work well for mobile, major tech firms like Google, Microsoft, Facebook, and Apple are searching for a solution. 
• One example: Facebook is using Atlas Solutions, the ad server it bought from Microsoft, to develop a "cross-platform solution" meant to replace the cookie. 
• Microsoft and Apple have both released traceable unique identifiers for their smartphones and tablets, while Google is using email to track users. 

Dive Insight: 

With mobile use eclipsing desktop, its easy to see why major mobile-tech firms are scrambling to find the next "cookie" for mobile. Since the cookie technology doesn't work well with mobile, these firms have to sort of reinvent the wheel to be able to target consumers as well as they could on desktop. The winner of the race will have an extra advantage if its solution becomes the standard.