Not having an address is a very big deal. As the United Nations' Dr. Joan Clos has been quoted as saying, "If you do not have an address, you do not officially exist." Without a postal address, you can't get a bank account, file taxes, sign contracts, receive government assistance, vote, or even apply for a job. "It's an indicator of who you are," Global Address Data Association founder Charles Prescott told Wired. "It's a tool people use to distinguish human beings."

Geocoding companies like Addressing Homes and Addressing the Unaddressed have been working to solve the problem in individual regions by assigning numeric or alphanumeric codes to previously unaddressed locations. But What3words takes a different tack by using dictionary words instead of complex codes. They overlay the world with a grid made up of 10-foot by 10-foot (3 meter by 3 meter) plots, 57 trillion in all, and names each with a three-word phrase.

For example, the White House is located at 1600 Pennsylvania Avenue NW, Washington, D.C. When you enter that address into What3Words, it lets you know that spot is called engine.doors.cubs. But that's just smack dab in the middle of the building. Want to find the Oval Office? Well, that's metals.deeper.hits — that is, unless you want the southmost point of the room, then you're looking at loud.goal.deeper. You can imagine how this level of precision could be incredibly useful for rural areas, where roads are scarce and signposts are scarcer.

That's why the government of Mongolia has adopted the system for their postal service, known as the Mongol Post. Nearly a quarter of the population is nomadic, so they have no permanent address, and many of the streets are unlabeled. Of course, for that to work, the addresses need to be translated into the Mongolian language. That's a drawback to the three-word system: a universal geocode isn't worth much if it's not, well, universal. The fact that What3Words is a private company is also a problem, since it charges for access to its database of which addresses correspond to which GPS coordinates. That makes it hard for government and nonprofits to take full advantage without paying a lot of money.

In that sense, other geocoding systems might be better suited for those purposes. But as Margaret Rhodes writes in Wired, "It's a big world—certainly big enough for more than one mapping system."