Head over HERE to sign up for Cheerios Coupons. You will receive $1/1 Cheerios coupons each week for 4 weeks (via email). I just signed up and here is my response:
Thank You for signing up.
Over the coming weeks you will receive 4 emails each with a $1 coupon.
If you win a free box of Cheerios® cereal, you will be notified by mail
in the next 6-8 weeks.