Why Facebook Also has to go "Mobile First"

BTIG analyst Rich Greenfield notes that the biggest problem with Facebook is uncertainty about Facebook prospects in the area of mobile advertising, where Facebook has virtually zero market share at the moment.

To keep matters in perspective, the U.S. mobile advertising market is growing far faster than expected, but remains a smallish part of overall online advertising, or advertising in general. 

eMarketer estimates mobile advertising spending in the United States reached $1.45 billion in 2011, up 89 percent from $769.6 million in 2010. U.S. mobile ad spending probably will grow on the order of 80 percent to $2.61 billion in 2012.

But that remains a smallish number, compared to total U.S. advertising spend.