According to LA Biz, GOAT -- an athletic acronym that stands for 'greatest of all time' -- is a mobile marketplace where sneakerheads can buy and sell their collectible shoes. Retro Air Jordans, Yeezy Boost, and Adidas NMD_R1 sneakers are all on sale on the site now.

But GOAT isn't an open marketplace. Rather, when sellers upload their sneaker listings to the app, they're required to take seven photos of the shoes so the company can verify their condition and authenticity.

Then when a customer buys them, the seller ships them to GOAT's warehouse in Culver City, California (not to the buyer) so the company can inspect them by hand and clean them before passing them on to the buyer. If the sneakers turn out to be fake, the customer gets a full refund.

'With the number of replicas flooding the sneaker market, our authentication service is becoming increasingly necessary,' co-founder and CEO Eddy Lu said in a statement, adding that more than 10 percent of premium sneakers on the resale market are fakes.

GOAT plans to use its new capital to grow both domestically and internationally, including expanding its team with strategic hires in engineering, product and marketing.

San Francisco venture-capital firm Matrix Partners led the round with participation from existing investors Upfront Ventures in L.A. and Webb Investment Network out of San Francisco. GOAT has raised $12.6 million total. Other investors include Andreessen Horowitz, First Round Capital, NEA, SV Angel and Y Combinator.

'Traditionally, consumers purchasing rare or vintage sneakers online had trouble finding what they were looking for, and then couldn't be certain of authenticity,' said Josh Hannah, general partner at Matrix, who will join GOAT's board. 'With GOAT's simple mobile app and commitment to verifying authenticity for every order, they provide a convenient and secure marketplace for sellers and consumers.'

Launched on iOS and Android just over a year ago in July 2015, GOAT has more than half a million members whose orders average more than $300. The company is averaging 40 percent month-over-month revenue growth.