(i) Public interest groups or promotional groups represent some common or general interest that need to be defended.
(ii) They promote collective rather than selective good. They aim to help group other than their own members. For example, a group fighting against bonded labour fights not for itself but for those who are suffering under such bondage.
(iii) The member of a public interest group may undertake activity that benefits them as well as other too. For example, BAMCEF (backward and Minority Communities Employees Federation) is an organisation largely made up of government employees that campaigns against caste discrimination.
(iv) Public interest group perform a useful role of countering the undue pressure put on the government by a small group of rich and powerful people and reminding the government of the needs and concerns of ordinary citizens.