The Installer writes with news of yesterday's stock offering from LinkedIn, which shocked investors by closing at more than double the initial price. "Buyers crowded the floor of the New York Stock Exchange, and financial news networks flashed LinkedIn's stock price urgently all day. By the closing bell, the company had a market value of $9 billion, the highest for any Internet company since Google had its initial public offering seven years ago. Millionaires and even one billionaire were made, at least on paper. The stock, issued at $45, went as high as $122.70 just before noon and closed at $94.25 on a trading volume of 30 million shares." That price values the company at over 30 times its 2010 revenue, leading to speculation that this is either evidence of the second dotcom bubble (a possibility we discussed in February) or a "watershed moment for social media." Many experts are questioning the value of LinkedIn, while others are claiming intentional market manipulation.