Bart Ehrman's Latest Book, "The Triumph of Christianity"

I haven't read it yet, but it looks very good. It's getting a lot of five star reviews and accolades on Amazon. It seeks to explain the rise of Christianity from being a forbidden religion with just twenty peasants or so, in rural Galilee, to "the dominant religion in the West in less than four hundred years." See for yourselves: The Triumph of Christianity: How a Forbidden Religion Swept the World. Any comments from people who know of it?