Look at Compete data: average stay of 15 minutes * 350 million visits/month = 87.5 million hours / month in the US. That is coupled with decent demographic data and ability to target. How much would that much attention be worth in TV or newspaper advertising? A lot more than Facebook is currently getting, I suspect.
If it can convince major brands that Facebook eyeballs are worth the same as traditional advertising (in effect sell them CPM, not CPC - "Facebook is the new TV"), then Facebook will do quite well. That's a very tough sell for smaller players, but it might not be impossible for Facebook.
Turns out that blanket, weakly-targeted advertising just doesn't perform that well, and companies get explicit feedback from these networks on just how bad the typical ad really is in terms of ROI.
If I run the same ad on tv or print, I have nowhere near the ability to accurately attribute any delta in sales activity to that specific ad run at that specific point in time.
You're probably right about that being the only form of ad they can monetize, though. The question then becomes when do companies spend as much in that space as they do on tv, if ever?
Brand advertising works because most consumers rely on a recognition heuristic when faced with the dozens of products in a store. They'll buy products they recognize, even if they have no personal experience with the product. You don't go out and buy an All-New Mercedes Benz immediately because you saw it on TV - but when it comes time to buy a car, you're far more likely to buy it because of all the associations that its name & image bring up. You can't measure this with any existing web metrics - it may be years before customers actually go out and make a purchase.
Put yourself in the position of an ad exec who has $n dollars to spend on his campaign and has to present to a superior how effective it was. If he has a web ad placement, the execs in charge of the money are going to immediately query him on what they got out of it (how much traffic they got from it). Adsense has spoiled companies into being far more demanding on number metrics on effectiveness. I can't think of 1 flash ad, branding or not, that does not have the option to click and learn more about the product. They are measuring the ad resonance, transaction driven or not.
The fact of the matter is, companies want a return on their web ads they can quantify. They measure using stuff like this: http://www.vizu.com/
When they don't get it, branded or not, they leave: http://mdurwin.wordpress.com/2007/07/25/corporations-leave-s...
I'm not sure most consumer product companies know how to do it properly.
Also some brand advertising isn't always about gaining ground, its about not losing ground to competing brands that do advertise, if Pepsi is pushing a huge TV campaign, Coke feels the pressure to play catch up.
I think they're going to have to look at membership or some other direct charge to users, and that's going to really affect that inflated valuation.
The social graph gives companies the data they need to target this kind of advertising. However, this means companies need to be less exploitative and work more with their consumer. I see this as being a bigger benefit for smaller, more personable seeming companies.
You need to focus on getting paid. Fast.
EDIT: In other words:
if Money In - Money Out > 0: Success
if Money In - Money Out < 0: Fail
The number of users doesn't matter.
And volume is no substitute for probability if every "consumption" is at a loss. Sony can sell the PS3 at a loss because it makes money on the games and in the long run, wins. They can't sell the PS3 at a loss and sell the games at a loss, and make up for it with volume.
That's what facebook seems to be attempting. And they're not even winning the volume game.
All the lovers will come and razz Matt and this comment, but none of them will be able to provide any evidence that facebook is doing anything but spending capital.