Finding the right place to deliver the message

Thanks to AdverBlog for reporting on an interesting campaign from Portugal. For those of you like myself who can't read Portuguese, the copy (click on ad below to view larger size) says "this gesture is repeated by millions of people each day."

I like this idea a lot because it pivots to an important message from a common ordinary action we all make frequently and without thinking, in the moment when we are making the motion.

I am not sure it would be a good idea to include a funds collection box in a public restroom - but I still wonder how this idea could work harder.