Go and sign up > here <. Then click on the Old Navy promotion listed right on the main page. At exactly 5:40 pm EST tonight they will be giving 9 people $100 cashback on orders over $100 at Old Navy! Make sure your order is over $100 BEFORE taxes. You will want to be logged in and ready to go before that time. If you are not sure what time it will be in your time zone just use this link to sign up and check out the timer so see how long until it goes live. GOOD LUCK!
The only exclusion I see on the Old Navy offer is that “Currently you may claim a maximum of 1 limited quantity “Members Only” offer every 30 days (one per store/brand every 90 days). Any offer that you claim but do not redeem will still count towards your limits (you have 0 remaining). A single account per household or computer network/IP address may claim offers marked as having limited quantities. To see offers you have successfully claimed visit your Saved Offers page.”