A few days after he was inaugurated as president in March 1933, Franklin Roosevelt revived a communications tactic he'd introduced as the governor of New York. Though even then many Americans still didn't have radios, Roosevelt gave an address from the White House that was broadcast over the radio airwaves. The subject was an ongoing banking crisis, part of the fallout from the depression from which the country was still struggling to recover.
Part of the appeal, though, was how Roosevelt spoke. Directly. With familiarity. It was a novel use of a new medium.
Week after week, Roosevelt continued to record these addresses. The tradition fell out of favor in the era of television, but was revived in 1982 by Ronald Reagan. Once every seven days, presidents would record messages about the country or their policy priorities, and radio stations would air them, usually on a weekend morning. There were occasional lulls - George H.W. Bush only did it sporadically - but it was a tradition that continued through the presidency of Barack Obama.
Once President Donald Trump came into office, though, the tradition faltered and collapsed.
For the first year of his presidency, Trump was fairly consistent about recording the messages. They were taped in advance and then published on social media sites like YouTube. By mid-to-late 2017, though, at about the same time that Sarah Sanders transitioned in as Trump's press secretary, the videos became more sporadic.