Anthropologist Devaka Premawardhana arrived in Africa to study the much reported "explosion" of Pentecostalism, the spread of which has indeed been massive. It is the continent's fastest growing form of Christianity and one of the world's fastest growing religious movements.
Yet Premawardhana found no evidence for this in the province of Mozambique where he worked. His research suggests that much can be gained by including such places in the story of global Christianity, by shifting attention from the well-known places where Pentecostal churches flourish to the unfamiliar places where they fail.
A must-read book (link)