I have a short list of places that to me speak loudly and poetically of San Francisco. Mission Pie is one of them. When I have visitors from out of town, I take them to Mission Pie. When I travel, I bring goodies from Mission Pie.
First and foremost are the eponymous pies, both sweet and savory. The crusts are made from soft Sonora wheat flour, and filled with ingredients that lead a better life than you and me. There's a map on the wall that shows you the nearby farmers and ranchers whose produce they feature, the story behind which they write about on the whiteboard near the oven.
Second, there's the fact that they are by and for the community, in every way imaginable. They hire young folks from the neighborhood, treating them with love and respect. They offer a small selection of locally made items, including the spectacular Kika's Salted Caramels, sweetened with palm sugar and made around the corner. They help other entrepreneurs like Josey Baker get their start.
When you shop small and buy locally you get qualitatively better products and services. You also keep money circulating in the local economy.