According to a report by the Interactive Advertising Bureau, online ad revenue jumped 15% to $26 billion in 2010. That's a sharp reversal from a 3.4% decline during the recession of the previous year.
Search advertising once again took the biggest share of revenues: 46%. That was down slightly from 47% the previous year, but the search category as a whole grew 12% in 2010. Display advertising accounted for 38% of the market. That's up from 35% in 2009. The display ad market grew by roughly a quarter in 2010.
The biggest category expansion, however, came in sponsorships, which grew 88% in 2010. The fourth quarter alone saw a 142% increase in sponsorships.
Other highlights from the IAB's report:
Classified advertising accounted for 10% of revenues for 2010 or $2.6 billion, which was up 15% from 2009's $2.3 billion.
Lead-generation revenues were down 8% to $1.3 billion.
Email marketing revenues fell 33%, to $195 million. That's just 1% of the market.
Mobile advertising, which hadn't previously been included in the IAB's report, is now estimated to account for between $550 million and $650 million.
The report also looks at who is paying for those ads. The leading spender once again: retail stores, which bought 21% of inventory last year.
Telecom and financial services were second and third, respectively.
A full copy of the report is available here.