This wasn't "5 million total viewers", this was "5 million incremental Prime subscribers specifically attributable to a desire to view these shows because it wa

This wasn't "5 million total viewers", this was "5 million incremental Prime subscribers specifically attributable to a desire to view these shows because it was the first thing they streamed". It would be analogous to HBO counting the number of subscribers it has added simply because of GoT or West World, but not to counting the total number of viewers for those shows.