I was looking for an unused voucher in my mailbox to go with the 50% off deal and found this. I don't think it's targeted (seems like it's targeted now). It says coupon expires 30 days from received.
Terms and Conditions
$20 off is available on purchases of $100 or more (before delivery or click and collect cost) and is available on online at briscoes.co.nz or in any Briscoes store. To redeem this offer, you must mention or show this email in store prior to payment or be logged into your account on the website and enter coupon code TWENTYOFF at checkout. If you don't have an account please create one or click forgot password to reset your account. Offer available for 30 days from when this email is received. Code must be applied at checkout and doesn't apply to previous purchases. Discounts exclude the purchase of gift vouchers. Personal shoppers only, trade not supplied. No phone or mail orders, no rain checks. If a refund is requested, we will refund you on a pro rata basis across all items that was purchased in the order. Offer cannot be used in conjunction with another coupon code.
Doesn't seem to work online. I'm going in store later today so I'll try in person