The Republican Party's presumptive nominee for president has started using online advertising software from ad-tech company Rocket Fuel that can help the campaign track user behavior, send targeted messages to prospective supporters and engage with fans.
CNBC.com learned of the addition by using Ghostery, a browser plug-in that shows all the data tracking tools running on a website.
Hillary Clinton and Bernie Sanders turned to ad-tech software early on in the Democratic primary cycle, as did Ted Cruz and others on the Republican side. Trump, by contrast, has boasted of the leanness of his media effort, counting on messages to his many millions of Twitter and Facebook followers, plus all the free attention he gets from non-stop news coverage.
That strategy wasn't going to work in a general election against the well-capitalized and data-heavy Clinton machine. According to reports last week filed with the Federal Election Commission, Trump had $1.3 million in the bank at the end of May, compared with $42 million in the Clinton coffers.