It says "It doesn’t get bigger than this: save 20% off everything in stock during Koorong’s five-day sale!".
While there definitely used to be a 25% off sale, but I am happy with it (especially when we were just talking about buying books for friends).
From Thursday 22nd February to Monday 26th February (web store open on Sunday 25th), save 20% off all our books, Bibles, CDs, DVDs – everything in stock. Also free postage for orders $99 or more.