Clothing manufacturers have caught on to an insidious, yet effective, marketing strategy -- women like to wear smaller sizes.
"I have everything between a size 0 and 8 actually, so I'm kind of at a loss as to what size I actually am," said one shopper, Wendy Chao.
Since high school, Chao said she has gained 15 pounds. Back then she thought she was a size 6 -- yet now, three skirts, sizes 6, 4, and 0, all fit her.
"If you compare all these skirts, the measurements are all identical," she said. "They could have been cut from the same pattern."
Even a size 0 skirt Chao bought just last year is swimming on her.
"Since it's a 0, I assumed it's the smallest that they had" she said.
But Chao was wrong; size 0 is not the smallest size out there. In a home video shot during a recent shopping spree with friends; Chao discovered something even more eye opening.
"This is me in a double zero!" she said in the video, while jumping up and down with joy. "I'm a double zero! Let this be proof to all mankind!"
While amused and thrilled that she could fit into a smaller size, the Harvard PhD student in molecular biology found size 0 and 00 absurd.
"When I'm measuring some light units and I get zero, that means I have nothing," she said. "I'm obviously not nothing. I'm not a vacuum."
But considering pop culture's obsession with thinness, for many women no size is too small.
"I had, one time, a client who said, 'I get into a 10 now,' " said Bridgette Raes, a fashion consultant. "She was originally a size 14. When she could get into a 10, and then into an 8, she was like, 'I know that it was a lie, I know that this really isn't a 10, but I love the fact that the label says 10.' "
That may be the thinking behind vanity sizing -- which means clothes are cut bigger, but sized smaller.
"Manufacturers and brands are trying to really make women feel good about buying their brand," said Marshall Cohen, a retail industry analyst. "If you were worried about being a size 14 or 16, I can make you feel great by a size 10 or 12."
One size 0 could have a waistline of 28 inches, which is, according to American Society of Textile and Material, a size 10.
The reality is that American women have been becoming bigger and bigger over the years, according to national survey. Today, the average American woman is 5 foot 4 and a size 16.
"Marilyn Monroe used to be a size 14," Cohen said. "In today's standards -- she'd be a size 8 -- now a size 8, soon going to be a 4 in a couple of years. That 4 is gonna be a 0, and if you wear anything smaller than that you'd be a negative size."