Game Diva is run out of Liu's Long Island, N.Y., home. In her basement and garage she stocks 200,000 games and toys. The holiday season is critical to her $500,000-a-year business. And this year she's betting big on the new Super Mario Brothers game.
"I've bought twenty boxes," Liu said. "And each box has 12 games in it."
On eBay alone, there are now more than a million e-tailers, like Karen. Many are hoping to cash in on the must-have gift.
"They're realizing that they can go to a store and try to predict what's gonna be hot, buy a ton of them and they can make money," said Cat Schwartz, of eBay.
Jennifer Canty has used just that model to build a $10 million a year business: dyscern.com.
"We've pretty much doubled our sales every year," Canty said.
From stores and manufacturers, she buys returned or overstocked electronics, like iPods, Blackberries and digital cameras, refurbishes them in her Virginia warehouse and then sells them online.
"We do have are great deals on those specific products that we brought in," she said.
Like the rarely discounted 8-gigabyte ipod nano. It's one of her Web site's featured deals this season, which accounts for 35 percent of her business.
Price and convenience are the main incentives luring people to the Web. More than 20 percent of shoppers say they plan to do all of their holiday buying online this year -- that's more than ever.
That's why Internet sales are expected to jump more than 20 percent this season to $33 billion. Rising gas prices and slumping home values may have the malls worried. But not the Game Diva.
Karen Liu can barely keep up with the shipping, because the shoppers keep coming -- to the Web.