Actually it's not. Because pretty rapidly your regulars get to understand this, and don't book standard fare tickets but turn up ticketless when "last minute" bargains are offered. It was one of the things that did in "Standby" cheap transatlantic tickets introduced a generation ago to combat Laker Skytrain. Each month more and more passengers, notably regular business travellers, was found to be diverting to people turning up on the day who understood the likelihood of getting away was good. On the commercial side this is known as "revenue dilution", where low fares offered are taken not by additional passengers but by those who would otherwise have paid higher fares.
I agree your point there!
Across the board cut price fares will lead to dilution. However, pro active yield management and marketing can work wonders with publicity. Virgin never seemed to grab the "yuppie" or stag weekend market.
I think the mistake was concentrating on the feeder service only!