Market Street, United Supermarkets’ all-in-one grocery store, opened this morning in Plano (W. Park @Preston). The first 100 people through the door will receive free milk for a year. As an added bonus, all 100 milk drinkers will become bloggers on SideDish. They will talk about milk every day for a year. Oh, this is going to be so fun. It just makes me Twiter all over.