US organizations on the political left are most likely to spend big on Facebook and Twitter ads; on Google, the trend is reversed, new research reveals.

Facebook seems to carry the highest number of political ads overall; but Google apparently ranks higher in impressions and for spending.

These insights emerged from research released by New York University’s Tandon School of Engineering, in which scientists used the latest machine learning and data-scraping tools to compile the first database of political advertising in the US.

The findings are based on analysis of over 884,000 ads identified by Google, Twitter, and Facebook (including Instagram).

The researchers behind the Online Political Ads Transparency Project said that, although they encountered some barriers to transparency from the media platforms – mainly with regard to what constitutes a political ad – the results throw up a series of meaningful insights.

President Trump and his Political Action Committee (PAC) placed the largest number of ads, due mostly to the large amount of micro-targeted advertising. Almost all these ads were aimed at raising cash during the study period, between September 9 and 22 this year.

Earlier this year, researchers from New York University also revealed the President was the single biggest political spender on Facebook ads alone between May and July this year. His PAC spent $274,000, far outstripping the $188,000 of the second-highest spender, the Planned Parenthood Federation of America.

The result was that the President’s ads were seen by 37 million Facebook users, the highest number for political ads.

The Democratic candidate for Senate from Texas, Beto O'Rourke, was the largest single spender on Facebook and Twitter; his ads were mainly for donations from outside his state.

Meanwhile, the Senate Leadership Fund, a Republican Super PAC, was the largest spender on all three platforms – Google, Facebook and Twitter – combined.

The fact that Facebook has more political ads than Google is due in part, the researchers said, to the large number of small, micro-targeted ads on Facebook (60%).

In contrast, most of the spending on Google (61%) is by PACs, which tend to have large budgets. They accounted for 23% of all political ad spending on Facebook during the study period.

Sourced from New York University; additional content by WARC staff