In-house ads are taking up the majority of space on mainstream news sites, as publishers struggle to convince advertisers to make the leap from print, according to new research.

The study, performed by the Pew Research Center's Project for Excellence in Journalism, looked at 5381 ads across 22 different news organisations in the US and found that 21% were ads selling or promoting the organisation's own products.

The financial sector was next, with 18%, while no other sector reached over 5%.

While Facebook and Google have built their business models on targeting ads to users based on their tastes and browsing habits, news organisations are failing to follow suit, with only three of the 22 tracked companies employing high levels of targeting.

Rich media ads using techniques like animations, videos, and site takeovers are also rare, with static banner ads the most prevalent in the study.

"Even the top news websites in the country have had little success getting advertisers from traditional platforms to move online,” the report reads.

"What will happen [in the news sector] pivots in part on whether the news industry can move into the more lucrative areas of digital advertising, particularly using consumer data to target ads, persuading major legacy advertisers to also advertise online, and moving into new revenue areas.

Do you think mainstream news sites could be targeting their ads more effectively? Do you find online ads more or less engaging than those in print or on TV, or are they all equally invisible?