Economic use of wildlife can be consumptive or non-consumptive, commercial or non-commercial. Given the economic preoccupation of virtually all modern societies, wildlife of economic value or use is favoured for conservation. However, does its commercial use favour conservation? This depends largely on whether private property rights exist and are enforceable. If property rights can be economically established and commercial use of a species is profitable, a strong force exists for preservation. On the other hand, if private property rights do not exist and there is open-access to commercially valuable wildlife, the tragedy of the commons is liable to occur and species may be driven to extinction by commercialism. Farming of a wildlife species is one form of commercial use, but it does not necessarily favour conservation of biodiversity. Nevertheless, commercial farming of some species may be environmentally more favourable than others, e.g., farming of kangaroos rather than sheep or cattle in parts of Australia. Commercialisation and choice based on economic value .has selective impacts on the populations of living things. It changes the composition of species. It therefore alters the natural web of life and is bound to be unacceptable to followers of Aldo Leopold who saw virtue in the land ethic. The general tendency of commercialisation is to reduce biodiversity and thereby sustainability even though it may save some species from early extinction.