Africa presents the world's largest untapped geographic opportunity. Behind Asia, Africa is the world's second biggest continent by land area, the second largest by population, and the second fastest growing economically. Considering the impact that the emergence of Asia has had on the world in the past 50 years, we can get a glimpse of the potential in the African continent.
To drive home the point about size, China, India, the contiguous U.S., and most of Europe combined could fit into the African landmass. Africa's population is also enormous. It's about 1.3 billion today, but that is expected to rise to 2.5 billion by 2050, at which point Africa will likely be the most populous continent in the world.