Facebook, a $100bn virtual empire in the making

From Singapore to Silicon Valley, bankers, bloggers, stock market traders and internet entrepreneurs are holding their breath. Facebook's record-breaking stock market listing, the largest ever for a technology company, is imminent.

The world's leading social networking site, with 800 million members worldwide, is expected to sell a 10% stake for between $7.5 billion and $10 billion in May, implying an overall value of $75 billion to $100 billion.

Most of the income will be from advertisers. WPP, the world's biggest marketing services group, spends $200 million a year with Facebook, compared with $1.6 billion with Google. But WPP chief Martin Sorrell has "fundamental doubts" about the extent to which social platforms can be monetised.

"Facebook is a social medium, not an advertising one, like search or display. It certainly is one of the most powerful, if not the most powerful branding medium. It is, however, a word of mouth or PR medium. You interrupt social conversations with commercial messages at your peril," Sorrel said.

Facebook founder Mark Zuckerberg was initially cautious about foisting advertising on his followers, to the extent that it led to a parting of ways with his co-founder Eduardo Saverin. The commercial coyness is long gone, and moves to monetise the audience with new forms of advertising have often provoked backlashes.