Advertising that’s good for you

As someone that made my undergrad thesis on ambient media this almost sent shivers down my spine. Small ones, anyways. But the idea is brilliant, isn’t it? Best of all this is as green as it gets. Very few trees had to be cut to transmit this message, and if so these were chalk trees.
The only thing I was lacking was a call to action of some sort, and maybe who is this message from. But you can do this in other media, so it’s good as is. Many points.