Allbirds, the sustainable sneaker that's growing in popularity without a big brand name

A brand of unknown sneakers billed as the "world's most comfortable shoes" has quickly found its way onto the feet and hearts of Silicon Valley.

Meanwhile, celebrities like Mindy Kaling, Julianne Hough and Jenna Dewan Tatum are hopping on the bandwagon.

Allbirds, a shoe company that tested its idea on crowdfunding site Kickstarter, quickly amassed about $119,000 in five days. The merino wool footwear retails for $95, and is the brainchild of former professional New Zealand soccer player Tim Brown and San Francisco–based engineer Joey Zwillinger. For the holiday season, Allbirds is throwing in a set of shoelaces.

The company's investors include Lerer Hippeau Ventures, Slow Ventures, Peterson Partners, Western Technology investments, Dave Gilboa, co-founder of Warby Parker; and Jeff Raider, co-founder of Harry's, among others. Since launching in March, it has raised $7.25 million dollars in capital.

Outside of some pop-up stores, the sneakers are mostly sold online, and the company told CNBC it took years to perfect the sneaker brand before it launched 10 months ago.

Allbirds
Source: Allbirds

"In the middle of the footwear market, the casual footwear market, what I like to call the Foot Locker world, there was a bunch of what was seemingly average product which hadn't had a lot of innovation." said Brown, who was initially interested in the opportunity to make a fashion-forward casual shoe.

At the time, Brown was playing football professionally and sponsored by sneaker giant Nike. He noticed the amazing running shoes and performance footwear in the market, but the lack of a middle market shoe inspired him to create Allbirds.

The sneaker is crafted from New Zeland's superfine merino wool — unlike most modern models made of synthetic wool — and is the reason behind the flagship shoe's name, the "Wool Runner." The fabric boasts the ability to minimize odor, regulate temperature and excess moisture. The shoes can be worn without socks and tossed into the washing machine for cleaning, features that have contributed to their success.

The company also has made a big push into keeping the brand as eco-friendly as possible: Allbirds said its carbon footprint its 60 percent smaller than a typical synthetic shoe and its packaging uses less material as well. The company's push to what Brown calls "thoughtful commerce" is what consumers are increasingly interested in. Consumers are caring where their eggs come from and now where their apparel materials come from.

Deborah Findling | CNBC

The company declined to comment on how many pairs it has sold since the launch, but hinted that it has far surpassed earlier estimates. However, Brown told CNBC that when Allbirds initially pitched the product, its prospective investors laughed at the projected numbers but invested anyhow.

In the 10 months the company has been live, Brown claimed it actually surpassed that figure four times over.

"We will be bringing out a new product, possibly new products in 2017," said Brown, adding that the company would keep their plans "pretty close to our chest. We're pretty fired up about what we've got in the pipeline."