Check out the note we got from PrintingForLess.com:
Project Name: 2009 Business Cards
Although you originally ordered 4 business day Production Speed, we have given your order special priority in our state-of-the-art manufacturing facility so that your shipment went out today, and should be delivered by 01/29/2009.
Please note that this special service is at no additional cost to you. It is simply our way of saying thank you for being our customer.
And they follow it up with this:
The Lesson: Surprise your customers with a free upgrade and then remind them how important their referrals are to you.