United is advertising that you can "fly almost anywhere in the U.S. for $75" with their latest sale, but truth be told, they're offering many routes for much less than that (from $14). United hubs have the most choice in this sale, but we're really seeing extremely heavily discounted fares from almost every city the airline serves. It's also good to keep in mind that all flights booked before August 31st can be changed or cancelled for free.
United Domestic Flight Sale Timeframe: 14. Aug. 2020 - 31. Mar. 2021