Thanks Don!
I'm Steve, the designer/art director of Derby Deck, and Shannon is in charge of the illustrations. I really appreciate your offer to educate us on the finer points of card design. I'm a complete newbie to this world, but a print designer by profession.
One issue we've already grappled with is the Queen of Diamonds having a full-bleed colored background, and it was a tough call. We like that card so much aesthetically that we couldn't bear to bring in the background's margin and lose the amazing detail in the watercolor wash that Shannon painted. My ears are definitely open to any changes you think we might need.
That background into the bleed is one of the issues that make the deck less practical. When cards are printed like that, you can actually spot them by looking at the edge of the deck - a real no-no for functionality. I would suggest a slight size reduction combined with a "soft border" - a gradual fade as the image nears the edge of the card so it's white before you reach the die line. I think you'd be able to preserve either 100% of the art or damn close to it. The reduction need not be large - you could shave a single percentage point or perhaps two and be far enough from the edge. One thing to be cautious of, especially with USPC, is that they focus on trying to get good registration on the card backs, since an off-center back is not desirable to anyone. This means they focus a little less on the faces, which in turn means you really need to "color within the lines" - make the border whatever their minimum spec happens to be. Thin-bordered backs are still pretty popular, but it drives their printers insane with how little margin for error some artists give them.
Speaking of backs... Yours has a very obvious one-way design. This in itself is not a bad thing, per se - but because of the fact that a deck can be stacked in a way to allow for identifying certain cards based on orientation with such as design, poker players will for the most part stay away from them. Even a hint of being a cheat is anathema to them. I would suggest making a "good girl/bad girl" deck pair as a stretch goal - make one back with the heart-bearing "good girl" and the lighter of the two background colors used, then make the other back with the knuckleduster-wielding "bad girl" in war paint and the darker background color. Poker players love a poker set - two matched decks in different, easily-identified colors.
From a marketing standpoint, it's not a good idea to use the Ace of Spades art as your tuckbox face art - it's great but it's also really not representative of the art in the rest of the deck. Take a joker or a lovely court card image with a roller girl on it, something that's both attractive and looks more like the other cards (or at least like the court cards, if you don't go with unique art on all the cards) and I think it will make a difference in sales, especially in the retail market after the Kickstarter project is completed.
As soon as is possible, I highly recommend getting more of your deck's artwork on the KS page - I would even suggest shooting a brief video explaining the theme and perhaps include real roller girls juxtaposed with their images on the cards (I'm assuming that many if not all of the cards are modeled on real players). A good video is only about 60 to 90 seconds long and doesn't have to be a special effects extravaganza - it would consist largely of your and Shannon's thoughts on the deck, why you made it, why I should buy it, what is your campaign offering as rewards, etc. A good video can make the difference between having or missing some additional sales.
But failing that, get more still images out there. People love to see what they're backing, and so far you've only shown the box, the card back and five faces. In an art-heavy deck, that's not enough. Show off images of the rewards - signed decks, postcards, uncut sheets (ESPECIALLY uncut sheets, as there's a whole separate market that goes for uncut sheets, particularly when they're chock full of great art). Uncut sheets are also a great way of showing off at least a hint of what the uncut sheet will look like. For decks with customized courts/Aces and standard or near-standard faces, I've even seen an artist or two rearrange the card order on the uncut so as to place all the more artistic cards in the center, making it more attractive for wall hanging. They'll also organize the remaining cards to create either a quarter-page or half-page scheme of alternating red and black cards. For example, you could have the four aces dead center, ordered clockwise from top left as spades-hearts-clubs-diamonds, surround them with the matching court cards of that suit, then arrange the remaining cards of that suit in the same quadrant that the ace and courts appear in, so the entire sheet has the same order scheme as the aces in the center.
Oh, and don't forget the tuck boxes. There's a subset of collectors who'll buy decks not to be opened but to be ogled in a display case, sealed and pristine - they go for very attractive boxes, especially if they have appropriately-placed elements such as metallic foil or embossing, or if they use a fancy vellum paper or heavy card stock rather than the ordinary single-ply stock used on tucks. DISPLAY THE BOX, in its entirety and not just a image of the front obscured by a card. Honestly, everyone loves a gorgeous box. There's also options for printing the inside of the box, placing a foil lining in the box, etc. Of course, these features would all cost extra, so you'd be using them as stretch goals, but an attractive box never hurt the sales of practically any product that fits in a box!
OK, my fingers are getting tired! That's my two cents worth...I wish you much success with your project.
BTW: your postcard stamps that you mentioned in the rewards? They no longer exist, as a one-ounce-or-less letter is now the same price as a postcard and has been for a few years already. People just use the "forever" stamps or an equal value of stamps adding up to the current price.