Targeted Facebook ads helped Trump win 2016 US elections

Micro-targeted advertising on Facebook was very effective in persuading undecided voters to support Donald Trump during the 2016 US presidential elections, a study has found.

According to the researchers from the Charles III University of Madrid in Spain, Trump's team spent 44 million dollars on Facebook, with 175,000 different adverts during the 2016 election campaign, compared to a spend of 28 million dollars by Democrat candidate Hilary Clinton.

In order to carry out these campaigns, the messages are sent out to Facebook users based on various factors, such as their gender, location or political allegiance.

This increased the probability that a non-aligned voter would decide to vote for candidate Trump by at least five percentage points, according to the study. On the other hand, the results show that Clinton did not manage to increase support among her potential natural voters nor boost their participation in the elections. "Unfortunately, we do not have the necessary data to be able to understand why it worked for Trump and not for Clinton," researchers said.

In Trump's case, the impact of the campaign was strongest among voters who used Facebook regularly, those who used this social media as their main source of news and among voters without university or college-level education.