• by Philip Rosenstein , Staff Writer, July 14, 2016

Over the past three months, articles about Donald Trump have displayed the lion’s share of digital ads viewed on content about presidential candidates.

The study looks at TubeMogul’s platform data across devices from the beginning of April through the end of June. Tracking page titles and article headings, the report measures the proportion of ads served by TubeMogul’s platform that found their way to articles about either Trump, Clinton, Sanders or Cruz.

The majority of ads in the desktop sample of candidate articles were placed to content about Donald Trump. That share steadily grew from 50% of ads in April, to 59% in May, edging up to 61% for June.

While the percentage of ads displayed on articles about Hillary Clinton on desktop has also increased, it remains significantly lower than that of the GOP nominee. In April, 19% of ads were placed next to articles about her, a number that grew to 25% in May and 31% in June.

Overall, Trump has remained the candidate digital users seem most interested in reading about. This data corroborates a similar study conducted by content marketing platform ClearVoice through June, which showed that Donald Trump-related posts made up 53.1% of candidate-related articles, compared to 26.9% about Clinton.

When it comes to placing ads to candidate articles on tablets, however, TubeMogul found that Hillary Clinton surpassed the Republican nominee in June, Clinton 50%, Trump 44%, with Cruz and Sanders picking up the slack.

Data on mobile ads show that Trump-related articles retained the proportional majority of ads among the four studied candidates, retaining 53% of the ads placed to candidate articles in April, 56% and 57% in May and June respectively. The proportion of ads served to articles about Hillary Clinton rose dramatically from 12% in April to 33% in June.

The study also looked at total video ads served to political sites and apps from Feb. 1 through June 26.

Most striking is the dramatic rise of video ads served to political sites/apps on mobile. During the week of Feb. 1, around 1 million video ads were placed on mobile, compared to a high point of more than 6 million around mid-May. The total remained steady at around 5 million mobile video ads placed to political sites/apps throughout June.

The growing importance of millennial and Hispanic voters, two groups whose constituents are heavy users of mobile, and are more likely to interact with digital video ads, are plausibly the target audiences fomenting this increase.