• by Wendy Davis , Staff Writer @wendyndavis, August 10, 2015

The use of ad-blocking technology in the U.S. has surged since last year, according to a new report by Adobe and PageFair.

Forty-five million U.S. Web users, representing around 15% of Internet users in the country, now deploy an ad blocker. That figure marks a 48% increase from last year, the report says. In Europe, around 77 million people now block ads -- a 35% increase from 2014.

Adobe and PageFair -- an Irish company that promises to help publishers "restore blocked ad inventory" -- estimate that the use of ad blockers will result in $21.8 billion lost ad revenue worldwide this year. In the U.S., ad blocking is expected to cost $10.7 billion this year, the report states.

Researchers found that sites that draw "young, technically savvy, or more male audiences" are more likely to be affected by ad blocking. Visitors to gaming sites are "significantly" more likely to block ads than visitors to health, charity and government or legal sites, according to the report.

For now, relatively few people use ad blockers on mobile devices. But the report authors predict this could change with the release of iOS9 later this year, which is expected to make it easier for Apple users to install ad-blocking software.

Adobe and PageFair suggest that privacy concerns could drive even more people to install ad blockers. In addition to compiling data from companies about software installations, researchers questioned 400 people who don't use ad blockers about the technology. Specifically, researchers asked those people what would spur them to start using ad blockers. Fifty percent answered that they would turn to ad-blocking technology if their data was "being misused to personalize the ads."

A smaller proportion -- 41% -- said they would install ad blockers if the "quantity of ads increased" from the current rate.

The report comes just days after the digital rights group Electronic Frontier Foundation released the ad blocker Privacy Badger out of beta. Privacy Badger can block ads that rely on traditional cookies, as well as ads that rely on some newer forms of tracking, like canvas fingerprinting.

The EFF recently said that Privacy Badger won't block ads from companies that agree to stop collecting data when they encounter do-not-track requests.