The remote stand rebate is intended to offset the higher costs (eg. additional staff, bus costs, etc..) that are associated with operating from a remote stand. The exact amount of the rebate is decided in consultation with the Airport Operator Committee and is set as part of the annual fees for the year.

From my experience, the rebate is pretty much a wash overall. There is no significant financial benefit or penalty to an airline allocated a remote stand as a result of the rebate.