Unacast PROX is the #1 platform connecting beacons and other proximity sensors to online marketing platforms. AT SCALE. GLOBALLY. GROWTH AND FRAGMENTATION. There are already over 350 proximity companies worldwide and it is estimated that they will deploy more than 400 million beacons by 2020. WE CALL PROX THE PHYSICAL COOKIE. By collecting and harmonizing proximity data from the largest proximity solution providers in the world, we are giving local and global media platforms the opportunity to connect to a global set of proximity data.