I've gotten into the habit at my grocery store of taking a cart from the corral into the store rather than walking in and then taking one from inside the building. It's functionally no effort for me and its one less time a store employee has to walk that cart back into the building. The people who work at that grocery store are my neighbors and townsfolk, every cart I bring back in on my way is an opportunity for them to stand around on the company dime.