I say that because it works for both the people doing field service and the watchtower
for the people its easier standing than having to walk and you can have a chat with other jws as well
For the watchtower they tell the drones that the general public must make the first move(to stop the general public complaining about being pestered) but in doing so it means that they are not giving many magazines etc away but that suits the watchtower because magazines and even single page trats cost money and that seems to be one thing that the watchtower dont have