Imagine the scene: You are attending a business conference and you hit it off with a potential new customer. You are about to leave and hand them a business card. How does that business card look?
Both your printed projects and your promotional items, while often distributed separately, are they are meant to work together or show off one united marketing campaign.
Take a guess at the amount of emails you receive a day. Now think about the amount you delete without even opening. The same can be said about mail, promotional items, and whatever else your company uses to send information to your clients.