Daily newspaper subscriptions tend to be lower in rural areas, partly because many dailies have shrunk their circulation areas in the last 15 years. Rural areas without dailies have weeklies, but those don't do much national election coverage. In such areas, Trump was able to reach voters with social media and local TV and radio stations owned by conservative media conglomerate Sinclair Broadcasting, which often forced its stations to run pro-Trump commentary.
Trump frequently encourages voters to listen to him for the truth instead of the news media. He wrote on Twitter in December, "I use Social Media not because I like to, but because it is the only way to fight a VERY dishonest and unfair 'press'."
"What he's doing is, he is becoming the source, and they believe him," Rick Tyler, communications director for Texan Republican Sen. Ted Cruz's presidential run, told Politico. "It doesn’t matter if the people they don’t believe say he’s not telling the truth. Trump’s breakthrough is that he’s unencumbered by the truth."