Direct mail is proven to be more effective at lead generation, customer retention and customer loyalty campaigns than an other form of medium, including e-mail. Why? Direct mail can be targeted to a specific recipient. No incorrect or outdated e-mail accounts or spam filters that will reduce the number of recipients who see your message.
Copy can be longer without fear that the recipient will opt out. Direct mail is also portable, many hold onto relevant direct mail marketing until they can act on it, or even share it with others.