Microsoft Advertising often runs promotions for new customers, so that they can try out online advertising with us.
If you sign up as part of a promotion and qualify, you'll receive a promotional code through email. (Check your junk mail folder if you don't see the email.) You redeem your code in Microsoft Advertising. Then, we apply a credit to your account with a promotional balance if you meet requirements, such as a minimum spend amount.
To find out how to add a coupon to your account and what the requirements are for using a coupon, see Microsoft Advertising promotional offers (coupons)