Mobile site and app publishers including Facebook, Pandora and Twitter are rapidly taking over the mobile display advertising market in the U.S., according to new research from International Data Corp. In past years, ad networks including Google, Millennial Media and Apple received most of the spending on mobile display ads. Now publishers control the segment, thanks to very strong sales growth in the past year.

Facebook, Pandora, Twitter and The Weather Channel all registered strong mobile display ad sales in 2012 and all but Pandora popped onto the scene from zero sales in 2011, IDC says. As a result, publishers controlled 52% of U.S. mobile display ad spending in 2012, compared to the 39% they received in 2011, according to the IDC report, “2012 U.S. Mobile Advertising Market Sizing and Vendor Market Shares.”

“Mobile ad networks are losing market share to publishers, and we expect them to lose even more going forward,” says Karsten Weide, vice president of media and entertainment at IDC. “Networks, especially independent ones, are entering a difficult phase, in which, with an ever smaller share of revenue, they’ll have to compete with publishers, which will only grow in strength.”

The IDC U.S. mobile advertising report also finds:

• Strong growth in mobile advertising spending in the U.S. continues, even if annual growth rates continue to decline. The market grew by 88% in 2012 (down from 125% in 2011) to a total of $4.5 billion (up from $2.4 billion in 2011). Mobile market share within all digital advertising reached 11% in 2012, up from 7% in 2011. For 2013, IDC expects a growth rate of 55–65%, with spending coming in around $7 billion for the U.S.
• Mobile display advertising increased its market share of total mobile spending in 2012 by eight percentage points to 39%, versus 61% for search ads. Mobile display ads attracted $1.7 billion in 2012 compared with $0.7 billion in 2011.
• Among mobile publishers selling display advertising, Facebook was the No. 1 company in 2012 ($234 million gross revenue), followed by Pandora ($229 million), with Twitter coming in third ($117 million). In the ad network segment, Google still holds the top spot ($243 million). One change is that Millennial Media ($151 million) has taken over Apple ($125 million) to claim the No. 2 spot. Jumptap remains No. 4 ($90 million).
• Marketers spent $2.8 billion in 2012 on mobile search ads compared with $1.67 billion in 2011 and $0.74 billion in 2010. Growth rates have slowed significantly, down from 195% in 2010 to 127% in 2011 and 68% in 2012. Google still dominates the market with gross revenue of $2.17 billion and a gross market share of 79%.

More than 1,000 IDC analysts provide global, regional and local expertise on technology and trends in 110 countries, the firm says.