That "hangtag" is actually a little bigger than a purse's hangtag, look at the measurements and check them out on a ruler. A classic purse hangtag is usually about 1 x 2 1/4 inches, so if you hang that one from a bag it's probably not going to look exactly like a hangtag for a vintage bag. An actual hangtag would not have a keyring or a clip on it either but would hang from a ball chain. It would make a nice piece of purse jewelry and that's what a lot of us would probably use it for but how well it works as a hangtag probably depends on the bag you're putting it on and how well the color of the leather and the brass match up. If the seller includes the ball chain mentioned in the listing at no cost, I'd ask for it. It DIDN'T come from Coach with a keyring and clip, those were added by the seller.
As for whether it's genuine, it's hard to say. It's definitely NOT from a bag more than a few years old so it may not match up well with a classic bag. Personally, I don't like to see sellers listing hangtags separately since that usually means they either took the tags off a bag they were selling which cheats the buyer of the bag of an important part of the purse, or they've taken unfair advantage of Coach's policy of sending
free replacement hangtags to customers who need one, which seems just a bit dishonest to me when the customer is just going to turn around and sell it for a profit on Ebay.
You could make a hangtag/keychain like that yourself - call Coach and tell them you need a replacement hangtag in navy with brass hardware and give them the serial number of the bag (if they don't have navy in stock they'll probably just send a metal one) and buy a set that includes the clip, keyring and ball chain from an Ebay/Bonanza seller like Silver-Coach and make your own. Here'sjust one of the sets they sell:
http://cgi.ebay.com/MINI-ZIPPER-PUL...t=US_CSA_WH_Handbags&var=&hash=item99ab27a8d4
and more here:
http://desc.shop.ebay.com/silver-co...=1&_from=R10&_ipg=&_mPrRngCbx=1&_udhi=&_udlo=
or at Bonanza:
http://www.bonanza.com/booths/SCECKERT
I've redone a lot of Coach keychains as purse bling using their clips and chains, just be sure to check the measurements in the listings (they sell several diferent sizes and types of clips) against a ruler so that what you're buying is in correct proportion to the bag you're putting it on and that the opening in the clip will fit over the hardware - O-ring, D-ring, buckle, whatever - of the bag you'll be putting it on. The hardware isn't made by Coach but it's a close match and is probably what the Ebay seller of the navy keychain uses to make her pieces.
The purple bag in the other listing is genuine - I bought a different style in the same leather and color at the outlet earlier in the year.