Nov 15, 2010 15:25 GMT  ·  By

Another week, another crazy Facebook valuation. Based on transactions in secondary markets, Facebook is now worth about $41 billion, making it the third biggest Internet company in the US. The number has been growing at a steady pace for the past few years, reaching increasingly dizzying heights, but it's still very much a hypothetical valuation at this point.

Facebook is a private company with a handful of people, with CEO and co-founder Mark Zuckerberg leading the pack, controlling a big chunk of its stock.

However, some Facebook shares are being traded, with approval from the company, by former employees and others owning small pieces of the social network.

Being such a rare commodity, those shares can fetch some rather high prices, now reaching about $16 per share, putting Facebook's worth at about $41 billion.

That's slightly above eBay's worth, which is valuated at about $39.3 billion based on current stock prices. Of course, eBay is a publicly traded company which value is based on actual demand for its stock, rather than estimates.

Still, based on these estimates, Facebook is only behind Amazon, worth $74.4 billion, and Google, which is worth $192.9 billion, in the US when it comes to web-focused companies.

Facebook's value has been growing for almost three years now, but it seems to be accelerating recently.

While there's no doubt that Facebook is one of the biggest websites and one of the biggest companies of the moment, it's hard to know if the company's estimated valuation has anything to do with its actual worth.

And there is no way of knowing that until Facebook finally files for an initial public offering. Based on what Facebook has been saying so far, that may be at least a couple of years from now.

The reason why Facebook is not jumping ahead and filing for an IPO is that, while the company is growing fast, its revenue is still not spectacular. Facebook could bring in close to $1.5 billion or as much as $2 billion in revenue this year, depending on who's doing the estimates.