According to a tour guide, there are 64 ABC shops in the USA... 60 of these in Hawaii and 37 of them within a one square mile radius in Waikiki. Having seen one of these convenience stores on every block - sometimes two - I can believe it.
But it certainly does screw up any notions I had about the dynamics of market cannibalisation. McDonald's and Starbucks eat your hearts out, someone else has obviously figured out how to do it better than you. (At least in the - perhaps atypical market of Waikiki.)