I was on an itinerary, PHL-CVG-BNA-CVG-DTW (bought as a multi-city) where the CVG-BNA and BNA-CVG flights were the same flight number (5775?) operated by Chautaqua. It was the cheapest option for a one-way ticket from PHL to DTW. It was a 20 minute turnaround in Nashville, but I convinced one of the Comair agents in CVG to just put me on the next flight to Detroit. (There were weather delays in Cincinnati and Nashville) I did wonder if I would have gotten the 1000 miles or 0 since the "direct flight" was CVG-BNA-CVG.