The online staffing industry is a big market--and it's only getting bigger. According to research firm Staffing Industry Analysts, last year the market hit $1 billion and it's forecast to reach $5 billion by 2018

That's good news for established freelance marketplaces like Elance and oDesk. But it also means there may be some opportunity for newcomers.

And a newcomer has officially arrived.

Jason Chicola and David Abrameto--both former oDesk employees--quietly launched Rev, an online marketplace that serves as the middleman connecting business owners with freelance workers on specialized projects, in 2010. It's been in beta for the past 18 months but officially opened its two freelance services, document transcription and translation, two weeks ago. On Tuesday Rev announced it closed a $4.5 million Series A round led by Globespan Capital, former COO Craig Sherman, and CarMax founder Austin Ligon.

"Rev aims to do for online work what Amazon did for online retail; revolutionize the customer experience, category by category," says Ganesan.

So why do the founders think they can go head-to-head with, among other competitors, its former employer oDesk? Chicola, Rev's CEO, says the start-up's highly specialized nature sets it apart. Rev only offers two services, but Chicola quips: "We do those two things very well."

Chicola also cites the joie de vivre embedded in Rev's unique company culture. “We aim to be fair, social, and productive,” he says.

At first glance, that may not sound very unique. Until you realize that Rev is set up so that the company intimately understands the challenges and needs of both the corporate customer and the online freelancers. The company has a full-time staff of only 14 people--the rest of the team is made up of freelance workers that Rev contracts to complete each client task.

Working at home has a tendency to make people stir crazy, says Chicola. In order to combat this, Rev has created a social network of sorts, where workers can come to chat, swap notes, and talk about their work.

"[People need] relationships and recognition--the best aspects of being in the office," Chicola says. He says he got the idea for a cohesive online community from the workers themselves. When Chicola sends a group email to his team of freelancers he usually hides their emails, but he forgot to do that on one message. It turned out to be a fortunate mistake: The freelancers were itching to connect with each other and began to email and arrange Skype meetings to talk about Rev and their work.

Chicola believes that Rev’s philosophy of being "as invisible as possible to the customer, and as supportive as possible to the workers" will help the company establish a foothold in the industry.

Rev, which says it has more than 1,000 customers, offers audio transcription for $1 per minute; translating business documents is 12 cents a word. In the coming months, Rev will offer additional language-related specialized services.