Today, LinkedIn is going public and the professional social network's skyrocketing value should be a clue to social marketers that they can't ignore this B2B-oriented space. In a blog post, the company announced its initial public offering of 7,840,000 shares of common stock for $45.00 per share, and many analysts did not expect the social site's shares to skyrocket.

The company's shares have more than doubled to $104 at press time. This places LinkedIn's value in the neighborhood of $9 billion, and many analysts are quick to point out how impressive this is for a company that earned $15 million last year.

Growing share prices seem to mirror growing LinkedIn use. As Brafton has reported, the B2B-oriented social network hit the 100 million member-mark in March, and eMarketer data indicates that users are logging into LinkedIn more than Twitter. Plus, comScore data suggests the site surpassed Twitter in terms of unique visitors at the very end of 2010.

Social marketers should consider LinkedIn's growing user base – and its booming stock value – a sign that it's worth investing in LinkedIn marketing campaigns, especially for business-to-business brands. It seems this is already a priority for a number of businesses. LinkedIn accounted for 20 percent of B2B logins at the start of 2011. Marketers might consider that the company's popular news aggregator, LinkedIn Today, indicates it is a prime platform for sharing branded social content.