'You have to tell people why it matters'

Chris Sheldrick, the co-founder and CEO of digital address system what3words, says his big idea was to divide the world into a grid of three-metre squares, give each square a unique "address" and everybody would be able to tell firms where to deliver items.

He thought it was clear it would be vital in countries where numbered street addresses are non-existent - but he says he had to work hard at explaining it properly before others were convinced.

Video journalist: Jeremy Howell