This seems like a pretty decent deal from Paypal and eBay. If you spend $50 or more on Ebay Canada and pay by paypal, you will be credited with $10 free cash!
There are quite a lot of T&Cs regarding this ebay Canada offer, so I will paste the main ones in here:
Receive $10 cash back on your first purchase of $50 or more (excluding tax and shipping & handling) (“Offer”). Offer applies exclusively to transactions ebay when you use PayPal as the payment method. Offer begins November 19, 2009 at 12:00:01am ET and ends December 2, 2009 at 11:59:59pm ET. The maximum amount of cash back allowed per PayPal account is $10.00 (USD). The cash back will be deposited into your PayPal account by December 10, 2009.
To be eligible for the Offer, you must: (1) sign up for the Offer by clicking the link on the email or on the Offer page located at (2) open a new account or have a confirmed Canadian PayPal account in good standing, and (3) complete a qualifying purchase on eBay.ca no later than December 2, 2009 using your PayPal account, which has the same email address that is linked to your eBay UserID.
You can read the full T&Cs here.
Don't forget to check out The Big Deal page, where ebay does some great deals with free shipping.