Internet ad revenue surges past $20 billion

Alistair Barr | USA TODAY

SAN FRANCISCO -- Internet advertising revenue surged past $20 billion in the first half of this year, propelled by an explosion in mobile ads shown by companies including Facebook and Google.

Online ad revenue of $20.1 billion in the first half represents an increase of 18% over the same period last year, the Interactive Advertising Bureau, an industry group, said Wednesday.

Mobile ad revenue soared 145% to $3 billion in the first half of 2013, as Facebook and other big tech companies tackled the switch from desktop computers to smartphones and tablets.

"Mobile advertising's breakneck growth is evidence that marketers are recognizing the tremendous power of smaller screens," said IAB CEO Randall Rothenberg.