U2 stars Bono and the Edge are gambling on their biggest hit yet after investing millions of dollars in an internet storage company which is tipped to become the next Apple.
The singer and guitarist were announced as individual investors in Dropbox, a file-sharing service that lets users retrieve their photos, videos and documents from any web-connected device.
One of Silicon Valley's hottest properties, Dropbox has attracted 50 million users by word of mouth and is already valued at US$4 billion ($4.9 billion). The company plans to challenge Apple and Google in the rapidly expanding "cloud" online storage business.
Dropbox co-founder Drew Houston, who plays guitar in a grunge band, tweeted a picture of himself with Bono and the Edge to announce their investment.
Alongside his reputation as a global philanthropist, Bono has become a shrewd investor in web technology companies through Elevation Partners, a US$1.9 billion private equity fund, which he co-founded in 2004.
A US$270 million investment in Facebook, buying shares from employees between 2009 and 2010, has paid dividends.
The stake is valued at US$1 billion.
Bono and Edge were introduced to Dropbox by entrepreneurs, and investors in the firm, Ali and Hadi Partovi. The brothers created a Facebook music video-sharing app, iLike, which Bono endorsed.
Dropbox offers its storage service for free with a US$20 a month upgrade for heavy users - 325 million files are saved daily using Dropbox.