I like Vistaprint too!
They usually have lots of "free" offers on various other products to promote your business (you have to pay for the postage). I think its great that you can "try before you buy".
The downside is you get loads of emails from them - but I just ignore them until I actually want something.
The latest offer I have just bought from them is a wall calender where I could use my own photos and add my own text. They would usually be £9.99 to buy this was free (plus postage)!

Avocet