What is ecotourism? What are the arguments for and against ecotourism?

Ecotourism is tourism characterized by the efforts of tourists, tour operators, adventure companies, and the travel industry to lessen the negative consequences of tourism on the environment as well as on local cultures and economies.
Proponents argue that ecotourism generally promotes consciousness about environmentally and culturally sensitive travel options. Tourists are often from highly industrialized nations in North America, Europe, and Australia, and they usually visit less-developed nations in Central and South America as well as in Africa.
Critics argue that ecotourism is futile because it is merely consumerism with a "green" wrapping and serves as a mechanism for middle- and upper-class tourists to assuage guilt about exoticizing foreign cultures and locales.