As with all flash sales, a few catches apply, of course. You have to book between now and July 27. All of the discounts apply to nonstop flights only, and flights on Fridays and Sundays are not a part of the sale. Blackout dates do apply, but these prices are good for flights booked for both international and continental US travel from August 22 to December 13. Take a look at full terms and conditions before you book, obviously.
If you want to take advantage of this, though, just be sure to act soon, as these flights are sure to fill up fast.