For me, the valuation of FB is closer to a TV channel with an audience of c. 500m people for 30mins every day of the week. And one which shows ads to people based on their own interests. What's that worth? I'm not sure.
The comparison with a phone network isn't quite right because I can't see FB ever being able to charge for service.
But I agree with your point. I think Linkedin is far more likely to be wiped out than Facebook, but the market thinks different.
I like the TV analogy, it's perhaps more apt. Surely the point of any TV network is to show ads based on their viewers interests? Just FB is able to be much more targeted (at the same time they also have to compete with the huge over-supply of online display-ads, are my eyeballs worth more on facebook.com vs. joes-blog.com? I don't think so, which is the major issue with their current monetization strategy (EDIT: and they haven't shown that their targeting is significantly better than Google Adwords as of yet)).
I am confident though that they will find a way to make FB a seriously viable business. The list of things I use FB for is just so long, I don't see how they couldn't find at least one v. profitable workflow to tap into (organising a night out, checking-in on the night out, posting photos the next day, etc.).
There are things like adblock which allow you to fully experience facebook sans ads.
Yes, there is tivo etc, but you have to pay extra to get out of the ad experience (and it doesnt always work). TV ads are much more intrusive than FB ads, and I'd imagine TV-style facebook ads (like some websites that force you to sit through an ad) most likely will kill the platform.
Are you sure about that re LinkedIn? Given its narrower customer base and usage model, LinkedIn is already employing a freemium model and charging for a higher service level. Their actual users do constitute a revenue stream in a way that Facebook's never could.
The comparison with a phone network isn't quite right because I can't see FB ever being able to charge for service.
But I agree with your point. I think Linkedin is far more likely to be wiped out than Facebook, but the market thinks different.