U2 Bono. U2 frontman Bono made a savvy investment in Facebook in 2009. Photo: Getty
U2 frontman Bono's investment firm has made a profit of almost $US800 million on shares in Facebook in just a few years, but average punters looking to get in before the social network goes public should keep dreaming.
Bono's investment firm Elevation Partners - named after one of U2's famous songs - bought a $US210 million stake in Facebook in November 2009. That stake is now worth $US975 million - a more than fourfold increase.

It's a nice earner for Bono, who has been derided as the worst investor in America after losing hundreds of millions investing in Forbes Media, owner of Forbes magazine. Elevation also invested almost $US500 million in smartphone maker Palm just as it was being relegated to irrelevance by competitors like Apple, but ended up gettings its money back when Palm was sold to Hewlett-Packard.
Serial Australian entrepreneur and investor Matt Barrie, who is currently chief executive of Freelancer.com, was straight to the point when asked how the average punter could buy into Facebook on the secondary market: "you can't".
But many others have got rich from Facebook shares, as outlined on the Who owns Facebook? website.
On its most recent valuation, Facebook has grown by $US15 billion in January to be worth about $US65 billion. Just last June Facebook was worth $US23 billion.
The $US65 billion valuation was determined after one of Facebook's early investors, Interpublic, recently sold half of its 0.4 per cent share in the social networking site for $US133 million.
But given that Facebook, which now has 750 million users, is a private company, it is difficult for smaller investors to get in. Facebook is widely expected to be preparing for a $US100 billion initial public offering (IPO) next year.
Employees in private tech companies have begun cashing in their shares by using exchange services like SharesPost and SecondMarket.
These aren't regulated or monitored to anywhere near the same extent as public share markets but have allowed employees and early investors to cash out some of their holdings while giving other cashed up investors the chance to get in before the IPO.
Barrie said to invest in Facebook on sites like SecondMarket or SharesPost you needed to be "qualified as a sophisticated or professional investor" with about $US2.5 million in net tangible assets or $250,000 annual income over the last three years "for a start".
"Secondly they are using second market to consolidate the investor base by buying up employee stock, as there are rules in the US about once you have 500 investors you are basically forced to go public," he said.
"So unless you want to buy hundreds of millions you are out of luck. Most private tech companies have rights of first refusal as well so even if you found someone willing to sell to you, you'd be rejected."
Some Goldman Sachs employees attempted to bypass the 500 investor limit by joining in on a $US1.5 billion Goldman Sachs "special purpose vehicle" created specifically to invest in Facebook.
The US Securities and Exchange Commission is investigating the trading of shares in hot private companies like Facebook and Twitter on secondary markets. There are concerns that the markets may breach trading rules and that significantly fluctuating valuations could cause smaller investors to get burnt.
Vivek Wadhwa, senior research associate at Harvard Law School, recently wrote in The Washington Post that the secondary markets "have the potential to generate fraud on an Enron-like scale" and represent "a serious threat to the culture of innovation that made Silicon Valley great".
"There are basically no rules, no real disclosure and minimal registration of issues. Welcome to the Wild, Wild West," he wrote.
"We do need to provide a better way for technology company founders and investors to exit after they have achieved success. But does this have to be by selling stock to uninformed investors?"