US online advertising spend rose 23.2% Y-o-Y in H1 2011

"Internet ad revenues rose 23.2 percent—to a record $14.9 billion—in the first half of 2011, according to figures released today by the Interactive Advertising Bureau (IAB) and PricewaterhouseCoopers (PwC US). The rate of growth more than doubled year-over-year, as last year’s first-half ad revenues of $12.1 billion had represented an 11.3 percent increase over 2009.
Internet ad revenues for the second quarter alone also reached new heights, increasing 24.1 percent to $7.7 billion. That performance compares to last year’s same-period revenues of $6.2 billion, up 13.9 percent from 2009.
Display-related advertising—which includes banner ads, rich media, digital video and sponsorships—totaled more than $5.5 billion in the first six months of 2011. Display increased 27.1 percent over the same period in 2010, substantially exceeding the previous year’s growth rate of 16 percent. Digital video once again commanded double-digit growth—up 42.1 percent over a year ago, and moved close to the $1 billion mark with $891 million in half year 2011 revenue.
Display accounted for 37 percent of all interactive spend in the first half of 2011, with search remaining the leading online category at 49 percent of the total—nearly $7.3 billion. Search and Display each grew about 27 percent year-over-year, with Search more than doubling its previous year’s growth rate of 11.6 percent.
In other online ad formats, dollars spent on lead generation increased 25.4 percent over the same period in 2010, but classified ad dollars were down 2 percent and email spend decreased 34.2 percent.
IAB and PwC US looked at revenue models supporting online ads. Ads using performance-based models increased faster than ads using impression-based models, rising to $9.6 billion. Impression-based ad spend did grow by 10.8 percent, though that pricing model accounted for only 31 percent of total ads, down from 35 percent year-over-year."
Source:  Press release from the IAB, 28th September 2011