Amazon Canada affiliate program is actually referrals for products selling, so the affiliate rate is actually the referral fee rate, which is similar like commissions but it is not exact commissions.
Amazon referral fees are calculated due to the sold product type and the count of shipped items which is through your referral links.
If the sold item is CE Products, the referral fee rate is a flat rate which is 4%, no matter you sold how many items. “CE Product” is a qualifying product that is offered for sale in the “Electronics”, “Audio and Video”, or “Camera and Photo” sections of Amazon. For example, if your links help Amazon sold 1 camera, another guy’s link sold 20 cameras, both of you will get the same rate at 4%；
If the sold item is General Product, the referral fee rate is variable from 4% ~ 8.5%, depends on how many items you sold (shipped) in current month. Different rate is paid along with different tier which is based on shipped count, for example, if shipped 1~3 items, your referral fee rate is on the tier 1, which is 4%; if shipped 25 items, it is on the 3rd tier with rate 6.5%; Additional good policy item is when you are moved from lower tier to a higher tier, you new referral rate will be applied to all items shipped during that month.
Amazon Canada releases a referral rates chart which is the same as the below one (the data is based on current date: 2016 Feb 11):
|Total Items Shipped||CE Prd Rate||Gen Prd Rate|
|1 – 3||4%||4%|
|4 – 8||4%||6%|
|9 – 30||4%||6.5%|
|31 – 60||4%||7%|
|61 – 100||4%||7.5%|
|101 – 250||4%||8%|
(All info based on here )