Gigom called it. It looks like 2008 is the year of LinkedIn, which is, not surprisingly, one of the few companies that has experienced significant growth since the recession's acceleration in September. Surprisingly, though, the professional network's traffic has grown exponentially more than other career sites in that period. Linkedin has seen a 25% percent membership increase since September. There has been a 15% increase in Linkedin invitations in the last two months, and a 14% increase in the number of recommendations of members. LinkedIn has 30 million worldwide users and is now adding 1 million new users every two weeks.

Linkedin membership is sure to respond positively to the site's introduction of applications to their site. Amazon Reading List, Files, Six Apart’s Blog Link, Slideshare Presentations, Trip It's My Travel, Google Presentation, and Huddle Workspaces were added this week.

Other popular career sites, while showing growth the last few months, have not experienced the spike LinkedIn has. Visits to Simply Hired have grown by 11% since August; the site has been trending upward all year. Monster’s traffic, on the other hand, has remained relatively stable in this period. Careerbuilder has seen significant growth since the middle of August, but only 4% total in the last three months; Monster had a small uptick since September and is only up 2% in the last three months.

Craigslist jobs has seen significant growth since September, and is the only of these sites seeing the same growth as LinkedIn. Visits to Craigslist in general are down 4% in the last three months, presumably due to decreased spending (or resolved Missed Connections).

Unlike a lot of companies, LinkedIn is on target to meet its revenue expectations for 2008. It is projected to make between $75 and $100 million this year. Or is it a matter of LinkedIn being more the more social or effective of the sites?

By Mark Alvarez