If you believed that Twitter’s popularity was waning down, you may be just right – Facebook’s owned Instagram had garnered more app users attention than Twitter. According to a ComScore study reported by AllThingsD last month U.S. mobile users “visited Instagram from their smartphones more frequently and for longer periods of time than they visited Twitter”.

Mark Zuckerberg stressed the importance of Mobile  platform in an Interview at TechDisrupt earlier this month, after Facebook’s $1 billion acquisition of Instagram, there were a lot of question on the valuation of this image sharing app,some of them seem to have been answered by these numbers.

The challenge for Facebook is to find a way to effectively monetise the photo-sharing app and its own mobile experience.