The track will easily give the singer the biggest sales week of the year for a song. Katy Perry’s “Roar” just keeps getting bigger. Industry sources now suggest that her new single “Roar” could debut with 525,000 to 550,000 downloads sold by the end of the tracking week on Sunday, Aug. 18. Three days ago, … More Katy Perry’s ‘Roar’ Now Aiming to Sell 525,000-Plus Downloads in First Week