Critics of capitalism argue that it establishes power in the hands of a minority capitalist class that exists through the exploitation of the majority working class; prioritizes profit over social good, natural resources and the environment; and is an engine of inequality and economic instabilities.
Supporters argue that it provides better products through competition, creates strong economic growth, yields productivity and prosperity that greatly benefits society, as well as being the most efficient system known for allocation of resources.
reference: http://en.wikipedia.org/wiki/Capitalism