According to Tracy DiNunzio, the average woman has only worn about 20 percent of her wardrobe in the past year.
That stat is at the heart of Tradesy.com, the company DiNunzio started back in 2012. Tradesy.com, an online consignment shop and marketplace, is built on the idea that you can turn the other 80 percent of the items in your closet into cash.
In an interview on CNBC's On The Money, DiNunzio said her company is similar to eBay, but has a distinct advantage the online auction giant does not.
"EBay serves 14 major categories with the same kind of platform," DiNunzio explained. "Because we're only in fashion, we've been able to tailor our service to make it quick, easy and valuable for our sellers."
At brick-and-mortar-consignment shops, "you only make about 40 percent of the sale," DiNunzio said. Yet with Tradesy, "you pay a 9 percent commission, and keep 91 percent of the sale."
After signing up on the site, users post a picture of an item and set a price. If someone buys it, Tradesy will send the user a free mailing kit.
Tradesy's business model has netted it some large-scale investment. Just this week, the Santa Monica, Calif.-based company received $30 million dollars in new funding. Investors include Kleiner Perkins and Virgin founder Sir Richard Branson.
That bundle was on top of the $14.5 million Tradesy already raised.
DiNunzio said that new money will be spent mostly on "hiring in our data science team to make sure we can connect supply and demand and understand the products that are in our system."
To guard against counterfeit goods, Tradesy said they have a 100 percent authenticity guarantee. If something is not authentic, "you'll get all your money back and a big apology from us, " said DiNunzio.
Designer boots, handbags and even wedding dresses are popular on the site. But how do people know if their unused, unneeded, or forgotten clothes will be in demand?
"Anything that's in your closet that's in good condition is worth selling," DiNunzio said. "Somebody will want to buy it. "
On the Money airs on CNBC Sundays at 7:30 pm, or check listings for airtimes in local markets.