Assume that all of these are available to all customers unless specifically listed as member only like the Welcome Package. Also remember that any preliminary codes are just that and BN could pull it, change the details or exclusions anything prior to release so always a bit of YMMV until the final release date

Mini FAQ
Coupons should not work for PREORDERS , Nook, Legos, Rosetta Stone, Digital, Gift Cards, Memberships, etc. There are glitches where sometimes an excluded item will be allowed but assume that is the exception to the rule
Free Shipping is $25 (before tax/shipping) or with membership.
Max 3 GC on a single online order.
Online only a single code can be applied to an order
Return period is 14 days after delivery (possibly 30 days for members though I've never tried)
Online ordered items can returned to a local store unless it's classified as a web-only item then it's at the store's discretion to accept
The long standing Free 60 day Trial Offer was discontinued in late May 2016


STORE ONLY 15% OFF Coupons -- Unknown if multi-use or if will work on 40% Off Items
15% OFF Single Item Exp 12/31/2017 (I)
15% OFF Single Item Exp 12/31/2017 (II)
15% OFF Single Item Exp ?? (III)


15% Single Item exp 11/6 2:59am ET -- if these are all used I can post some more.
New codes added below at least to make the bots and lurkers work a little harder. Used codes removed 3:30pm. New Codes added




Some possible upcoming codes
STACKED
YESANDYES
DAYMAKER
TAKEFIVE

"New Member" Welcome Coupons
Welcome coupons may be dead -- or at least the type that have been available for nearly a decade. The latest set now have what appears to be single use codes so these probably no longer will be generic/multiple use style.