Have you and your family held on to Christmas cards through the years because, well you just couldn't bring yourself to throw them away? Your loyalty might be a bigger virtue than you ever expected, and valuable too. All of those old Christmas cards could be worth a small fortune!

Goodhousekeeping.com says that vintage Christmas cards in good shape can be worth anywhere from $10 to $50 a piece, but in some case hundreds of dollars.

As with most collectibles, you've got to know what to look for if you want to cash in.

The age of the card is one deciding factor, as I'm sure you've already figured out. The interesting thing about Christmas cards is, they're designed and sold to be used for only a short time. As a result, it's uncommon to come across one even 10 or 15 years old. Not all things old are valuable, but in this case it certainly can be.

Another thing to look for is if the card depicts a historic event or popular character.

Terry Kovel, co-author of the Kovels' Antiques & Collectibles Price Guide tells goodhousekeeping.com -

"Looking out for cards that tell a history, such as content alluding to a war or topical event, or even a popular toy of the time. Evidence pointing to a specific date can add to the card's provenance. Recognizable cartoon figures like Snoopy, Mickey Mouse, and Felix the Cat also have a specific market, and then there's the big guy himself."

Artistic value and condition are also deciding factors of a card's value, but if you happen to have a Christmas card signed by a celebrity, that's where the big money can start coming in.

According to Kovel "Maybe your grandfather knew someone of significance all those years ago, maybe they worked on a film set, knew an author, worked in publishing. The key bit that could add value is the signature. Everyone loves the signatures."

So, how can you find out if some of the old Christmas cards packed away in the attic are valuable? Read more over at goodhousekeeping.com for more info and to get started.