The IAB (Interactive Advertising Bureau) released its latest “IAB Internet Advertising Revenue Report,” revealing that online ad revenues in the United States reached an all-time high of $27.5 billion in the first half of 2015.

That figure represents an impressive 19% increase over the first half of 2014 when the report showed ad revenues of $23.1 billion.

IAB SVP of Research, Analytics and Measurement Sherrill Mane said, “Internet ad revenue growth is being driven further than ever before, as advertisers continue to invest in new ways to reach consumers. Audiences have rapidly altered their media and purchasing habits and made digital media and mobile devices an integral part of their lives.”

As the IAB points out, growth is only accelerating with Q2 showing a 22.5% year-over-year increase to $14.3 billion, up from $11.7 billion in Q2 2014. That’s also an 8.5% increase from Q1.

IAB President and CEO Randall Rothenberg stated, “Advertisers are more committed than ever to connect with audiences on digital screens. Content is key to winning consumer attention – on mobile, in digital video, on desktop, and more – throughout the day.”

The report found that mobile revenues reached $8.2 billion in the first half of the year, up from just $5.3 billion for the same period last year. Mobile now accounts for 30%of the revenues generated by the entire online ad marketplace, it says. That’s up 23% year-over-year.

Here’s a year-to-year comparison for different ad types:

“We’re witnessing a seismic shift in consumer behavior to the always-on, connected consumer,” added David Silverman, partner of PwC US, which prepared the IAB report. “As a result, we’ve seen social continue to fuel the growth of digital, particularly with respect to mobile and video.”

Digital video reached $2 billion in the first half of the year, up 35% year-over-year. Meanwhile, search revenues surpassed $10 billion up 11% over $9 billion for the same period in 2014. Social reached $4.4 billion, up 51%.

Display revenues were $6.8 billion for the half-year, up 5% year-over-year. Display accounted for 25% of digital ad revenues overall.

As the IAB notes, the same top three advertising verticals (retail, financial services, and automotive) still account for roughly half of ad revenue.

You an find the full IAB report here.

Images via Thinkstock, IAB