Facebook user map

Facebook has amended its IPO forms and the changes are significant. The social networking giant admits in the revised docs that while "daily active users (DAUs)" are on the rise, those numbers are outpacing the average number of ads delivered each day. AllThingsD breaks it down for us:

But as Facebook points out in its risk factors section, it’s all because of mobile. More than half of Facebook’s 900 million monthly active users (or MAUs) are accessing the site on a mobile device. But unlike its desktop ads business, the company has yet to truly monetize mobile.

TechCrunch points out that analysts associated with Facebook’s IPO roadshow are worried about how mobile usage will impact the site’s ad revenue. As the user base shifts from mobile to the web, Facebook is showing those users fewer ads. Investors may not want to wait while Zuck & Co. try to figure out less obstrusive ways to insert ads on mobile's smaller real estate. In his shareholders letter, Mark Zuckerberg may have said its all about prioritizing "user engagement over short-term financial results," but advertisers are not going to be happy that those mobile users are less enagaged with their ads.

Warren Buffett (Getty Images)

Warren Buffett and his Bershire Hathaway partner Charlie Munger  could care less about Facebook's big Initial Public Offering (I.P.O.) Road Show, which drops the needle tomorrow. While Mr. Buffett was somewhat diplomatic in explaining to CNN that his company never buys into offerings, Mr. Munger was as forthright as you might expect an 88-year-old billionaire to be:

"I don't invest in what I don't understand. And I don't want to understand Facebook," Munger said.

In fact, it's not only that he doesn't understand it -- it's that he dislikes the whole idea of it.

"I don't want people putting all this personal stuff into a permanent record when they are 15 years of age. I think it's counterproductive. I just basically don't like it."

Mr. Buffett kept his counsel regarding the appropriateness of using Facebook at all and told CNN that Facebook, Google and Apple are "fantastic companies. But in terms of what they'll be worth five or ten years from now, I just don't know."

Mr. Buffett, a.k.a. "The Oracle of Omaha" may also be thinking back to the dot-com bubble of 12 years ago. Back then the billionaire avoided cashing in on the tech stock boom of the late 1990s and ended up seeming almost psychically prescient:

"Value is destroyed, not created, by any business that loses money over its lifetime," Mr Buffett wrote.

He was referring to the business model all too many dot.coms employed - to enrich investors through rising share prices rather than profits.

Mr. Buffett has made his feelings about what may be a social media bubble crystal clear as recently as March, when he told Bloomberg that most social media sites--Twitter, Facebook, etc.--"will be overpriced."

"It's extremely difficult to value social-networking-site companies," Mr. Buffett said, "Some will be huge winners, which will make up for the rest."

Facebook is likely hoping they'll be among the winners.