LinkedIn has recently raised a $53 million round of funding from all of its existing investors, along with new investor Bain Capital. The deal values the company at over $1 billion dollars, founder Reid Hoffman tells me.

Speculation has swirled around the Mountain View, Calif.-based business social network, which has rejected multiple acquisition offers — including offers near the above valuation — over the course of its history.

LinkedIn, you see, is quite valuable. It has gained 23 million monthly active users, and it is making $100 million a year in revenue. The money comes in from paid subscriptions for premiums services, job listings, targeted ads, and its new corporate recruiting products.

We first reported the company’s funding round in April, when we heard that there’d been a momentous board meeting, although at first it wasn’t clear if the company had made a decision then about selling or not. Then, a couple tipsters told us that the company was instead raising a large round, a move subsequently confirmed by other publications.

In any case, Hoffman is clear about company’s future plans. It will use some of this funding to buy smaller companies that can help its users share information better — vague, I know — which may include companies building mobile applications and other services.

Then, once LinkedIn feels it has firmed its “foundations” and is a central hub for business communication, it will go public, Hoffman says. “We kinda think about an IPO when every new quarter comes around — but we’re not giving any particular kind of time frame,” he adds.

LinkedIn is working with other software companies to build out many services for businesses, and is looking at how to expand deeper into business software, as we’ve previously examined. Of note, it has been quietly working on its developer platform, which has been criticized for its slow roll-out. For example, it offers a script where business publications can link names of people and companies in articles with their profiles on LinkedIn. That service is being used by BusinessWeek, CIO, and more than 100 smaller publications, the company says. There is more to come on that front, but nothing now.

Existing investors include Greylock Partners, Sequoia Capital, and Bessemer Ventures, that have together put a previous total of $27 million into the company.

VentureBeat's mission is to be a digital town square for technical decision-makers to gain knowledge about transformative enterprise technology and transact. Discover our Briefings.