A Goodwill ambassador is an honorary title and often linked with non-profit related causes. Their primary function is to help non-profit organizations spread their message across.
Predominantly, goodwill ambassadors are celebrity advocates or known personalities, who use their fame and talent to get funding, donations, encourage volunteers to participate and raise awareness towards the organization's cause. If fully invested in the cause they are promoting, personalities can greatly influence the process of persuading others.
Organisations include united Nations, UNICEF, UN Women, UNHCR and UNESCO, all of which have celebrity Goodwill Ambassadors making appeals on their behalf.