Been using the rail replacement bus Manchester/Bolton like this Manchester - Salford Crescent (terminus Southport) x Salford Crescent - Bolton RRB. Now that bus has left at 10.55pm and has been virtually empty, whilst even midweek the train doing the same route has much more footfall getting off at Bolton. But the point is - because the train's normally there people use it; had there been no rail service many would not travel at all. So it's made me think, are there any really successful lines or additional trains where companies might otherwise have thought "there's no demand so we won't put a service on"??