Many people don't even know their own postal codes, let alone the addresses of their office, friends' houses, grocery store, etc., so 'what3words' is aiming to name every single segment of the planet with word addresses.
The hypothesis is simple: three words are easy to remember so use that for a street address, a postal code, a city, and a country. Capitalizing on this concept with the sheer size of languages, 'what3words' uses an algorithm to assign a unique three word code to each of the approximately 57 trillion 3 meter by 3 meter squares on Earth. Squares can be named anything, from "chill.once.waddle" to "stubbed.pining.petty."
More than a gimmick, what3words hopes to incorporate its word addresses into metropolitan areas to increase the accuracy and efficiency of deliveries, while improving mapping systems in less developed nations.