It's an interesting concept. I wonder if they have multiple poles around town, if you can return the scooter to another pole with an available slot. And if you are able to do that, does that mean you might rent a scooter from one pole and then go to return it to that pole, but not be able to, because someone took the empty slot you created.
I haven't looked into it closely, but
there are places in DC where you can rent bikes from stands, like luggage carts in an airport. I think it's a great idea.
Zip cars too.