[gilesrhysjones]

"Two thirds of the world’s population is without a postal address,” Charles Prescott, Executive Director at the Global Address Data Association

50 or 60 countries have postal code or address databases which are kept reasonably current...’ ... ‘In the least developed countries, address verification may only mean that the city or town exists in that country.’- UNIVERSAL POSTAL UNION

“Over 50 percent of the world’s urban dwellers do not have access to named streets.” Catherine Farvacque-Vitkovic, World Bank

That's around 4 Billion people without an address.