Facebook founder Mark Zuckerberg’s elder sister, Randi Zuckerberg has left her role as Facebook's marketing director; reportedly to set up “a mysterious soon-to-be-launched media company,” RtoZ.

Randi had been working at the company since 2005 - back when the company was still called Thefacebook – and she chiefly focused on marketing Facebook's activity around major news events.

Saying that she was leaving with “a deep love of Facebook,” Randi noted in her resignation letter: “I have spent my years at Facebook pouring my heart and soul into innovating and pushing the media industry forward by introducing new concepts around live, social, participatory viewing that the media industry has since adopted.”

Despite the fact that there has been no official disclosure about the details pertaining to Randi’s upcoming RtoZ media company, the nature of the responsibilities that she undertook at Facebook has led to speculations galore that the new company - of which Randi is the founder as well as CEO – will largely be “focused on the exciting trends underway in the media industry.”

In the opinion of industry commentators, Randi’s new RtoZ venture will inevitably lead to her working with her brother’s biggest competitors in the social networking arena - like Twitter and Google, whose latest Google+ social network has received quite rave reviews.