Serial entrepreneur Richard Branson has put his backing behind nascent blogging service Tumblr, contributing to an $85m investment which values the service at $800m.

The vote of confidence in the start-up comes despite the firm’s failure to generate any real revenue – or indeed come up with a business model to help monetise its growing popularity.

This has seen the site report 13 billion page views each month, up from just 2 billion at the start of the year.

Branson is joined by a raft of other investors unperturbed by such figures, including the likes of Sequoia Capital and Union Square Ventures, who all believe the site has the potential to rival the likes of Facebook and Twitter.

Tumblr president John Maloney said his goal was to “scale Tumblr to profitability” but would eschew traditional banner ads in favour of innovative advertising forms which work organically with the blog platform.