A new start-up called RentLogic has entered the New York City real estate market with a smart, simple idea wrapped around a proven business model. It provided a data product that rated rental properties on how well they were maintained. Unlike opinion-driven ratings sites like Yelp and TripAdvisor, RentLogic mines complaint and violation data from official government records, assessed them, and assigned every building a letter grade from 'A' to 'F.' It's a clever idea and arguably much-needed. A...