According to MediaPost.com citing stats from the Interactive Advertising Bureau and PricewaterhouseCoopers, Internet ad revenue rose 24.1% to $7.7 billion in the second quarter of 2011.

Combined with the results of the 1st Q 2011, Internet ad revenue totaled $14.9 billion in the first half of the year.

“For the first six months, display-related advertising revenue totaled $5.5 billion or 37% revenue, up 27% from the $4.4 billion reported in 2010.

Search revenue for the first six months of 2011 totaled $7.3 billion, up 27% from $5.7 billion in 2010 or about 1/2 of the total Internet Ad spend.

Banners took 23%, or $3.4 billion

Digital video rose 42.1% to $891 million.

Lead generation grew 25.4%, compared with the first six months in 2010, accounting for 5% during the first six months of 2011, or $805 million.

Ads using performance-based models increased faster than ads using impression-based models, rising to $9.6 billion.

In Q2 2011, approximately 64% of revenue came in priced on a performance basis, up from 61% reported in Q2 2010.

About 31% of Q2 2011 revenue was priced on CPM or an impression basis — down from 35% — and 5% of Q2 2011 revenue priced on a hybrid basis, up from the 4% reports in the year-ago quarter.

The study identifies the retail sector as the biggest spenders online.

Retail advertisers accounted for 23% during the first half of 2011, or $3.5 billion, up from $2.5 billion in the first six months of the prior year.

Telecom companies followed, contributing 14%, or $2.1 billion, up from $1.7 billion;

Financial Services, 13%, or $1.9 billion, up from 12%; and Automotive advertisers, 11%, or $1.7 billion, up from $1.3 billion.

The computing sector, spent $1.5 billion

Travel, spent $1.2 billion

consumer packaged goods $866 million

Entertainment, $556 million, up from $508 million

Media, $660 million

Healthcare, $608 million