It's got nothing to do with being right off 95, though of course that helps. It's got to do with that huge buliding across the street with the PRICELINE sign on it. I'm betting they have a large portion of the hotel booked on a very regular basis, either for their employees, or for people visiting them.
I use to live about a mile up the street, and worked in the Priceline building, it's a gold mine for any service related industry within walking distance.
I'm sure they get a fair amount of weekend traffic too, for some reason Norwalk is a summertime weekend destination. The childrens museum, the maratine center, IMAX, and a varitey of train packages from New York make it a getaway for many "city folks"