eBags makes extensive use of cookies to track your browsing and shopping habits if you have an account with them already.  So yeah OP, you probably have a coupon in one browsers cookies.
If you have an account with them, and find a bag you like that is not on sale (or is on sale and will be on sale for awhile), you can get 15% off pretty easily:
1 - Log into your account, make sure you stay logged in
2 - Add the bag to your cart
3 - Leave the site.
4 - In 1-3 business days they'll send you an email offering an additional 15% off the cost of everything in your cart.
(Also, you'll get 15% off anything else you add to your cart at this point, not just the items there were there before)
Their sale prices are typically well over 15% off, and unless you know a sale will be going on for awhile, it's better to just buy immediately.  But I've used the above method to get a few bucks off bags before that weren't on sale.