The CP shows the map, not the direct location, it is there regardless, even if it did, it is innaccurate due to loading time and user movement. Following someone would only be by map.
Putting in the the control panel makes it alot better if you want a distribution chart, maybe even a pie chart.
But, as for in game, it wouldn't work well simply because at 200 auto venders, that would either imbalance the graph, or crowd it.
Good idea, bad way of coding and displaying it.