(AP) -- Internet ad sales are on the mend as first-quarter revenue rose 7 percent, marking the second straight quarter of increase, according to the Interactive Advertising Bureau.
The revenue of $5.9 billion marks the highest for a first quarter, which is typically a slower period following high ad spending over the holidays.
Thursday's study by the IAB and PricewaterhouseCoopers says retailers are spending more on Internet ads as Americans go back shopping. Retailers accounted for 20 percent of all online marketing in 2009.
The rebound came after online ad revenue slumped for the first three quarters of 2009.
David Silverman of PricewaterhouseCoopers said that while uncertainty about the economy remains, the strong start in 2010 "is a sign of the health and vitality of online media."
In 2009, the height of the economic crisis, online advertising fell for the first time in seven years. Revenue dropped 3.4 percent that year to $22.7 billion.
Explore further: Amazon as an adult: Two decades of online shopping