Revealing that Facebook is on the threshold of achieving the enviable 500-million-user mark - a milestone that the company is likely to officially announce sometime this week, coinciding it with the launch of its new marketing plan called ‘Facebook Stories.’

The forthcoming announcement of its accomplishment of 500 million Facebook users will come just over a year after the February 2004-launched Facebook – which has steadily risen to become one of the ‘most visited’ sites on the Internet - announced its earlier feat of having reached up to 250-million Facebook accounts.

Going by the recent data – excluding Google sites - released by Google’s AdPlanner service, Facebook largely dominates the Web with 540 billion unique monthly visitors who dish out nearly 630 billion page views on the site. Facebook itself accounts for nearly 34.8 percent of all Internet users.

In addition, Facebook recently disclosed that it has also reached a landmark of 150 million mobile users; showing a nearly 50 percent increase over the Apri-this-year statistics of 100 million mobile users.

Meanwhile, the new ‘Facebook Stories’ feature that the social networking site will soon announce which essentially be a collection of short stories about users who have had their lives changed by Facebook. According to All Things Digital's Kara Swisher, the new feature will include upto-420-character tales by geography or theme - like, “finding love”; “coping with grief”; and “natural disasters.”