Google and Facebook already control 60.8% of the total US digital ad market. And when it comes to the duopoly's share of digital political ad revenues, it has an even tighter grip, with a combined 77.6% this election cycle.

Facebook is the dominant digital platform for political ads, capturing a 59.4% share during the 2019/2020 election cycle. That equates to $796.8 million*.

“Facebook offers reach, targeting capabilities and ease of use that appeal to political advertisers,” eMarketer forecasting analyst Eric Haggstrom said. “Candidates can more quickly and easily send ads to potential supporters compared with TV or radio. In a competitive election, timeliness, efficiency and relevancy are incredibly important.”

Google is No. 2 among political advertisers, capturing 18.2% of all digital political spending during 2019/2020. That equates to $243.7 million.

“Google has a smaller display business overall than Facebook, and its relatively lower political ad revenues correspond in part to its smaller display footprint,” eMarketer principal analyst Nicole Perrin said. “Facebook is also continuing to allow a range of targeting options for political ads, including custom audiences and lookalike targeting, which Google has disallowed.”

While eMarketer does not break out Google’s political ad revenues by format, we know most money spent on display ads goes to YouTube.

“YouTube is popular because campaigns can run the same or similar ads that they are running on TV, while reaching a different audience,” Haggstrom said. “Additionally, YouTube allows candidates to test and experiment with various ads before running them on TV.”

Search spending on Google is fairly steady throughout the election season, as candidates seek to have their names appear at the top of search results. Display and video ad buying usually spike a bit closer to the election, as campaigns buy ads to persuade voters to cast ballots.

*Our figures for Facebook political ad revenues vary from those shown on our Political Ad database. This is because the database includes spending that Facebook considers a “politically sensitive topic” but does not meet our definition of a political ad.