Being able to target messages communicated to specific groups of customers is an important asset for a company to possess. If they can provide content to groups of customers that is more relevant to them they have a higher chance of influencing their behaviour.
Take for example airlines, if they have specials running from one country or location, targeted communication will allow them to only communicate with people from that area. As a result the effectiveness of this communication relative to how many people it reaches will be much higher.
Twitter have recognised this need that businesses have and are now offering companies the ability to communicate their message to specific geographic areas. This ensures everyone from around the world receives the material that is most relevant to them.