The why : Time is money and attention is expensive. If your text babbles on and on, you’ll lose both. Conciseness is also aesthetic, and short lines pack a punch.
The how : Know what you’re writing about, write it – then delete most of it. Do your research, stick to the facts, and concentrate on the flow.
In this time of excess info, businesses (and consumers) are left struggling for space. If you find some, please don’t be a waste of it.