Even an inexpensive item such as this letter opener when direct mailed to a target demographic can produce encouraging results. Like the calendar concept, the letter opener will remain with the recipient, used every day and continually present its sales message.
The object with this specific item is to have it color coordinate with the business card. Also, I opted for the transparent red because it makes the user WANT to pick it up and feel it.
Remember: for a premium to be successful, it must provide an immediate, obvious benefit to the recipient.