Just ran a few more numbers. As you said, assuming similar COGS, SG&A, R&D as a percentage of Sales, all multiples based on Google (Revenue, EBIT, EBITDA and Profit) seem to point towards an equity value of 10-12bn. However, this would also be assuming that FB and Google have similar growth opportunities. The two companies are at different stages in their growth cycle with google being much more mature compared to FB.
I think there is huge speculation that that FB will exponentionally increase its user base with the takeup of mobile internet usage in less developed countries. Also don't disregards the fact that FB is slowly becoming the new marketing tool for companies as it enables them to directly interact, communicate and build relationships with clients. That will have a huge impact on advertising revenues.
The guys from Goldman aren't stupid, a value of $50bn could well be possible but I do believe that this is based on a lot of speculation with regards to userbase growth and expansion into other areas. I think the real bubble is yet to form once the stock goes public. I wouldn't be surprised if FB achieved a market cap of $100bn+ within the first 6 months of its IPO. Whether that's sustainable is a different story
. I certainly wouldn't put my money on it. Bottom line, I do completely agree. $50bn (as per Goldman) is possible but maybe a bit aggressive, $70bn is very aggressive.
I could also well imagine that either company is speculating on the hype around social media and the demand for their stock. Buy in now, set the IPO at a market cap of $80bn and make a killing in 1 year. Not unrealistic. If you ask me what the price will be in 5 to 10 years I would suggest $20-30bn.