Just to put it into perspective lets take BOH, where they charge a frankly ridicules £2.50 for drop offs. If you look on Skytrax before the charge was introduced the reviews were typically averaging 3-4 stars with a few at either extreme. However EVERY review after the charge is introduced is either 1 or 2 stars, and they all mention the charge as being stupid, unnecessary and a deterrent to passengers. All these charges do is put off and anger passengers, resulting in fewer of them choosing to travel from the airports which charge for drop off fees even if they are nearest to them. This reduces the revenue further, making the whole idea of the extra charge pointless.