Amsterdamproducts.ca is a Canadian office supplies site, which has the added bonus of offering lots of free samples! For any product you are interested in, click the "request a sample" button under the image. If the item is less than $5 in value, you can order it for free!
The company is probably doing this promotion to let people see the quality of their products, in the hope they will order more in the future. Shipping also seems to be free for these complimentary office supplies!
For example, this North American wildlife desk calendar is only $4.79, so you should be able to get it for free.
Now, I haven't gone through with my order yet, but it seems you can add more than 1 item to your cart! You can give this a try if you want, but I wouldn't order too much or they might just cancel your order. Don't be greedy!
Let us know how you get on, in the comments below.