Facebook has halted orders for its shares as the social network prepares for what some believe could be a $100 billion strong stock market floatation on 18 May.

The last few days have seen Facebook both issue a greater number of shares – an additional 25 percent on offer – and raise the price per share, jumping from between $28-$35 to $34-$38

Such a hike, of course, means the company's valuation has also risen, now coming in at somewhere between $93 billion and $104 billion.

Not all good news

So called 'regular' investors won't have a chance to pick up shares until the company floats on the Nasdaq in New York, though critics are already claiming Facebook's valuation is far too high.

Indeed, the social network's stock market debut is playing out against a backdrop of disparaging talk of the platform's advertising prowess.

General Motors has announced it is to pull all advertising on Facebook, claiming the platform has little pull on the average consumer's buying habits. The contract itself is worth $10 million, though it's the damage such talk could do to Facebook's reputation that will likely worry Zuckerberg and co. more.

The company has already admitted it is having problems monetising its now 500 million strong mobile userbase – a particularly salient point, given the increasing prominence of Facebook's smartphone apps.

[source: CNN]