Sir; While some of my fellow small retailers have expressed alarm each time a big company like Sainsbury or M&S has announced it is going to launch a c-store format, I have to admit it hasn't worried me in the slightest. The theory goes, the big companies will wipe out independents with their superb new stores, but that just doesn't happen in practice. The big companies find that running small stores, and making an acceptable return from them, is not at all like the business they are used to. So I am not at all suprised to see that M&S is looking to put its Simply Food format into larger stores. When will the giants learn that the economics of small stores will not stack up for them? Mind you, I would prefer it if they keep on trying. Perhaps they will be distracted from running their bigger stores which present a much greater threat to small retailers because of the way they draw shoppers away from towns and villages. S Shah Leicester {{LETTERS }}