This is quite common in the UK too, always worth visiting the supermarket in the early evening. 75% discounts are common, and 90% discounts are not unheard of. Sometimes when I go too early I see 25% or 50% discounts and think "pffft, is that the best you can do?"
On quite a few occasions I've walked out with a full backpack of food for about £6, and filled up the freezer. You even occasionally see news stories about people fighting in the supermarket over yellow sticker bargains.