When it comes to customer service smiling goes a long way. Whenever I was on the sales floor I tried to keep my big goofy smile plastered on my face. Granted by the end of the day when I was exhausted it gets hard to maintain it. Since good service was expected of me I've come to expect it as well. When I have a poor experience I'll typically avoid those businesses from then on, like Wendy's. It's one thing to be slow but to constantly deal with cashiers that do not smile is irritating.
I think one of the reasons why I continue to support convenient stores is that most of the time the people behind the counter are friendlier. No matter how many times I go into a grocery store I am seldom treated like a regular but even if I pop into a convenient store once every few months I'm greeted like an old friend.
When I start posting fliers for Satoshi Sneaker Shoppe I'll be hitting up my local convenient store.