Africa is growing into a sports betting powerhouse with South Africa, Nigeria and Kenya leading the charge. Legal gambling revenues across the continent is on the rise, reaching an estimated $9 billion. A young and growing population, rapid mobile technology adoption and a shift in consumer habits have all helped fueled the boom.While some researchers even argue that Africa's shared passion for football has opened the door for the betting industry. If you go into gambling shops, for instance, you'll find ou ...