Unless it's a small airline it can actually be an intelligent ploy on overcrowded routes. Big airline has two spare planes and wants to get in route A, which is crowded but has a high number of pax at both ends. Big airline throws both big planes on the route at 1 Euro. People get angry due to the money they're losing, as you did, and move to route B. Big airline now has an empty route, throw one plane off and jack up the price of the other. Wash and repeat. It's the 10 frequency which is useless. Not only does it lose everyone money but you can't use that same plane for another route as well as it taking up a tonne of gate space.
