How did Thom Yorke sell Tomorrow's Modern Boxes in September 2014?

As a BitTorrent Bundle: eight tracks and a video for six dollars, out unannounced on 26 September 2014, with “A Brain in a Bottle” free. Yorke and Nigel Godrich called it an experiment, and BitTorrent counted 1.1 million downloads, free and paid together, within a week.