Green Center Concept

I entered a concept for a 1 hour design challenge at core 77. The criteria was to come up with a concept to stop using plastic bags. My idea went like this: In a mall or shopping center setting, To have a bag with the mall or shopping center's name and advertisement on it. You would receive this bag after your first purchase at one of the stores. You would be charged a small fee for it. You would use it from store to store, then when you leave, you could either take it with you to keep; or return it for your money back.