1. A system for administering promotions in which a player is awarded any one or more of a priori promotion credit and a posteriori promotion credit to be consumed in wagering on house edge services and peer-to-peer services characterised in that substantially all of the a priori promotion credit and any substantially any portion of the a posteriori promotion credit that is redeemable for monetary value may be utilised by the player to make wagers on the house edge services; and substantially any portion of the a priori promotion credit that is not redeemable for monetary value is not utilisable by the player to make wagers on peer-to-peer services.