During a century one company controlled most of the diamond mines in the world. They are called The Beers Group. The Beers would stock pile most diamonds found and control the release to the market to artificially keep the prices up.
It has only been recently that large diamond factories started to create lab diamonds at industrial scale and increase that supply. Daily Diamonds buys directly from the country where the lab diamonds are produced. This is why we can offer lower prices than others.