Wrong....
If the surcharge was pure profit, Express wouldn't have gone to the effort of having CSAs generate shipping labels with all data entered into the POS while the over-the-counter customer was standing there. The surcharge merely offsets the costs incurred in having a CSA do the research, pulling the package out of the sort and other loss of system efficiencies.
Bad addresses COST Express business - the shipper EXPECTS the package to be delivered on time, REGARDLESS if they happen to make an error in getting the correct address on the package. The $11 only covers Express' cost in correcting the error and incremental loss of customer good will (each bad address costs Express just a little bit in lost goodwill).
If the surcharge created "pure profit", Express wouldn't give one lick that customers got the correct address on the package and would let the revenue roll in.