Is it harder to obtain new customers or keep the old ones?

It's much more difficult and expensive to obtain new customers than keep old ones. To get new customers, companies have to convince them that it's worth leaving their normal brand (for example, Verizon trying to convince Sprint customers to leave Sprint for Verizon). It's much easier and less expensive for a company to offer their current customers discounts or deals if they consider leaving for another brand (i.e. Sprint offering their customers a free month of service if they don't go to Verizon).