i've seen them around brisbane for a few years now. At bus stop advertisements, magazines, etc. Although I have no idea what they mean, what you are suppose to do with them, how to get the data, etc. Maybe this is one of their major flaws - majority general public do not know what it means or does.
ok, now I know what they are but what do I do with it? To me it just looks like a bunch of dots inside a square.
Thanks charttv, can i ask how youre tracking it.