Beside the fuelcosts and the pilotpay-costs each flight does also cause maintenance costs.
And such maintenance costs depend now also on the FPM (vertical speed) of the touch-down.
The softer the landing is, the lower are the maintenance costs of each flight.
examples:
landing rate of -139 FPM causes maintenance costs of 7%
landing rate of -227 FPM causes maintenance costs of 14%
landing rate of -500 FPM causes maintenance costs of 21%