An advertising industry group says revenue from Internet advertising in the U.S. hit $8.4 billion in the first three months of the year.

That's the highest for the first quarter, up 15 percent from $7.3 billion in the same period last year.

The record for any quarter is $9 billion in the final three months of 2011.

Record-setting numbers are a common occurrence, as more advertisers turn to websites and mobile apps, where they can target their pitches more precisely than traditional channels.

The Interactive Advertising Bureau, an industry group, conducted the quarterly study with PricewaterhouseCoopers.

The group did not break down the figures, but typically the bulk of the spending comes from text-based ads that are sold by Google Inc. and other companies. These ads are targeted to search terms and other keywords.