Six National Mapping Agencies Adopt what3words

The three words for an adjacent cell are completely different. Depending on where I click on my home I get different and unrelated results. Without their software to look up the location the three words are meaningless. I see no real advantage to this system.

So what was wrong with latitude and longitude?

Completely unique and offers better resolution than a 10' cell, doesnt need special software to decode it, backward compatible with maps and globes from many centuries.

I'm not sold on the new gibberish

I looked to see how swisstopo is using it. When viewing a web service, you can enter the what3words and it will identify the location, or if you click on a location and look at its info, what3words is one of the multiple pieces of information returned. So not replacing anything, just adding them as an alternative.

This sounds like a common core math solution to the question "So, where are you from, can I buy you a drink?"
😀

The drawback or craziness, as was pointed out, there's no way tell the relationship of 2 three-word identifiers. In other words, how far is 'holly.sugar.valid' from boring.locals.mull? Or, from 'newly.gone exact'? Or from 'crossed.duped.custom'?

The 3 words are random. So you can't plot them. It's a code to prevent determining relative location.