Merino rams are an important input in the Merino breeder's production process. Breeders need to make informed decisions when buying rams because of the influence that the ram will have on the characteristics of the herd, especially with regards to the characteristics of the animal that are deemed economically important. Before the advent of performance testing through objective measurement a system of subjective evaluation was used to determine the breeding value of Merino rams. The use of the subjective system of evaluation seemingly continues and the prevalence of this system of evaluation raises the question to what extent ram buyers are using performance measurement indices in aiding them in their buying decision. This study finds that performance measurements supplied to buyers are indeed used to determine the economic value of an animal. These performance measurements are, however, only responsible for determining a small proportion of the economic value of an animal.