Book excerpt: Down, down ... In hardware, petrol, general merchandise and liquor, and above all in groceries, Coles and Woolworths jointly rule Australia's retail landscape. On average, every man, woman and child in this country spends $100 a week across their many outlets. What does such dominance mean for suppliers? And is it good for consumers? In Supermarket Monsters, journalist and author Malcolm Knox shines a light on Australia's twin mega-retailers, exploring how they have built and exploited their market power. Knox reveals the unavoidable and often intimidating tactics both companies use to get their way. In return for cheap milk and bread, he argues, we as consumers are risking much more: quality, diversity and community.