"As the Americans learned so painfully in Earth's final century, free flow of information is the only safeguard against tyranny. The once-chained people whose leaders at last lose their grip on information flow will soon burst with freedom and vitality, but the free nation gradually constricting its grip on public discourse has begun its rapid slide into despotism. Beware of he who would deny you access to information, for in his heart he dreams himself your master."
Generally, you don't just sit and listen. You do it while doing something else that is non-audio, like commuting or exercising or cleaning or cooking or...
If millions of people each like Oprah enough to give her a dollar, she makes millions.
(pardon the napkin math) If you live in a town of, say, 25k people and your town has 10 garbage collectors (napkin math: each pair covers 1000 people's trash every weekday) each earning minimum wage 15k/year (if it takes 1min to pick up trash for an average household of 2, we get just over the standard 2k work-hour year. To me this sounds like fast operation and low house size. But the low end of the trash costs demonstrates the point), then each person in town is paying $6 to their garbage collectors. Even more considering benefits and non-labor costs. If healthcare, garbage truck maintenance and, I dunno, landfill fees (are those a thing?) cost the city a mere 100k/year, every person is paying $10 for garbage collection.
So in the napkin scenario, for each individual, garbage collectors are valued at 10x what Oprah is. And that's with all my napkin math assumptions choosing the lowest costs. Plausible scenarios could go as high as 100x individual value for garbage collection over Oprah mic talking. But Oprah can do her less-individually-important job for 1000x more people. It's an issue of reach.
IANAE but it sounds like when imports get cheaper, importers pocket as much of the the difference for as long as they can get away with it. When imports get more expensive, they pass on as much as they can to consumers as quickly as they can get away with it. Not terribly surprising for profit-driven behavior.
Would the war have actually ended early if Germany had taken Paris? With the British and Russians still unmolested on their own turf, wouldn't the French have tried to retake the city instead of surrendering? Or at least their allies keep fighting? (I realize this perception is colored by how it played out in WWII so I'm curious whether it would also apply to WWI)
When does she ever change future events? Sure she needed knowledge from the future to make that future happen but that's just a time loop, not altering the foreseen future.