Betting Agencies This page provides a one-stop reference for betting agencies that are suitable for Australians. The agencies listed here all offer Australian dollar accounts. Agencies fall into two categories: bookmakers and exchanges. Bookmakers are agencies that set the odds and you bet against the agency. With exchanges, the odds are determined by fellow users within a marketplace, so you bet against fellow users. Bookmakers are recommended for beginners, while an exchange membership is a must have for serious enthusiasts, because it enables you to bet against outcomes.