Despite the fact that e-commerce has been around for decades and still only makes up 6% of US retail sales, Rajiv Lal, Jose Alvarez and Dan Greenberg see stormy clouds ahead for brick and mortar businesses, reports Harvard Business School. And it’s not just small businesses that have to worry. Their book, “Retail Revolution: Will Your Brick and Mortar Store Survive?”, predicts a retail apocalypse so big even Walmart is vulnerable. In a nut shell: now that Millennials are walking around with computers in their pockets, online shopping is everywhere, and our society is becoming more like Sandra Bullock in The Net. But it’s not all doom and gloom for brick and mortars. The book has three defense strategies based on what the authors call TIPS, an assessment of a business’ strengths and weaknesses in technology, inventory, people and space, compared to e-commerce competitors. [HBS]