4 device whose serial number is the wonderfully unique "0123456789ABCDEF". Presumably if we had more than one unit we would have a problem. These are called engagement audiences. They show the level of engagement a user has with your sitio. They are broken out to tell you which users http://alexandre-de-moares48158.look4blog.com/20574461/indicadores-sobre-queiroz-voc-deve-saber