Money back for the situation (s) you described is not going to happen regardless of the length of the delay. Compensation may be forthcoming and could range widely depending on the individual airline. In some instances, a monetary voucher may be offered or frequent flyer miles or a voucher for a free trip (extreme cases) or maybe even just a letter of apology. But to answer your question, yes, delays do cost the airlines money. In fact, Gordon Bethune-CO indicated the his airline saved at least 6 million dollars annually when their airline operated as on-time as possible. Costs can really start racking up when airlines delay passengers making connections, especially International connections because now the airline needs to "protect" these passengers on other (full) flights and quite often on other airlines. There are too many situations to enumerate here regarding the cost to airlines associated with delayed flights. It's simply good business for an airline to run on-time.