Ah, the Christmas sweater. Bedecked, bejeweled, bedazzled. So ugly it's downright beautiful. Nanas everywhere, along with lovers of irony and all things ridiculous, cherish this annual tradition as much as any other.

For the inevitable Ugly Christmas Sweater Party, most of us have only to look in our nearest thrift store for apparel that fits the bill. But if you want to do something truly spectacular this year, you should check out UltimateUglyChristmas.com, a vendor of the most hideous – and hilarious – sweaters you will ever see.

Run by Marquette University High School senior Jack McCarthy out of his parents' basement in Wauwatosa, UltimateUglyChristmas.com began in 2008 when McCarthy's older sister brought a particularly unsightly Yuletide sweater home from college. She had worn it ironically in a 5k run.

"She spent about $5 for at Goodwill and she didn't want it anymore, so we put it on eBay and it ended up selling for about $50. We were surprised that it created a bidding war and people actually ... wanted them," said Jack. 

The teenager realized that there was a thriving market for tacky Christmas apparel, which can usually be bought for almost nothing. Thus was born UltimateUglyChristmas.com, where McCarthy retails spectacularly kitschy Christmas sweaters for prices ranging from $15 to $35. 

McCarthy scours thrift store and flea markets all over the Midwest searching for the unsightliest specimens. The sweaters are available for purchase all year long but McCarthy says business really picks up around Christmastime. He recruits his high school friends to model the sweaters and his sister, who lives in the Twin Cities, helps out with social media marketing. His mom helps out with shipping, now that homework and college applications are beginning to leave McCarthy snowed under.

But other than that, says McCarthy, as for the business, "it's pretty much me." 

He has sold over 1,200 so far just this Christmas season. "It's getting down to less than a hundred as Christmas approaches," he says.

So just what constitute ugly? "We don't want to insult any of the readers," McCarthy laughs. "Just your craziest grandma sweaters – my favorites are the ones with the zippers on the sleeve, or with the most eye-popping designs. That's what we look for."

The site also has tips for throwing parties and having the perfectly awful decor, music and food.