Big cities, the next business opportunity

Talking about big markets, the number of people living in cities of over one million is 25% of the world population.

But mega cities grow weirdly, inefficiently and organically. In short, million+ city inhabitants are probably the biggest business opportunity on the planet right now.

(FWIW, The Economist reports the number went up from 15% to 25% over the past six decades, making this a strong trend)