Metro released a printable coupon on their facebook page for 40 bonus Air Miles when you spend $40 or more in a single transaction.  This coupon is limited to one per customer and will only print once, so make sure your printer is attached and working before you click print.  40 Air Miles is worth $4.20 in Air Miles cash, or even more if you use dream rewards.

This Air Miles coupon expires on August 21st.  Click here to print your coupon (facebook account not required).  You can use coupons to reduce your total but since it is a printable coupon, you may find cashiers will not scan the coupon below $40.  This coupon cannot be combined with other Air Miles coupons but you can make use of in-store Air Miles offers.