Marketing greeting cards are an effective way to advertise a service or product while giving the reader a bit of a boost. Free greeting cards with jokes, pictures, witty sayings or cartoons are a smart idea as the reader will likely keep the greeting card or pass it on to a friend.
Have a series of business greeting cards (or personalized business greeting cards) printed up as a nice way to market by strengthening customer/business relations. Customized business greeting cards make the reader feel special--as if the direct mail campaign is aimed only at him or herself.