According to the technology blog TechCrunch, Elevation Partners, the private equity firm backed by bad-backed U2 frontman Bono, has stumped up $120m for just over 0.5 per cent of Facebook.

The deal values the dominant social network at $23bn, and takes Elevation Partners’ total stake to 1.5 per cent, having invested $90m at a $9bn valuation last year.

Reports earlier this month claimed Facebook’s sales were between $700m and $800m last year, so Bono and friends reckon it’s worth about 29 times revenue at the moment. Which is a lot.

Elevation Partners mission is about helping media and entertainment entrepreneurs develop and deliver content, leverage new platforms and channels, namely social networks and social media assets.

Facebook is still growing at an incredible rate, and recently hit 500 million users, further fueling hopes that the still private company might seek to go public sometime soon, but most IPO observers have said they don’t expect Facebook to file anytime this year, even if the market gets a slight psychological boost from the Tesla Motors Inc.IPO on Tuesday.

So Elevation probably will likely be holding its investment for awhile.

Venture Beat reports also that Bono Vox has invested on its own too in the social network, in addition to the Elevation Partners deal, along with founder Roger McNamee, showing a strong confidence in Zuckerberg’s idea and project.

More info are available here and here.