Walmart has opened a new front in the war for e-commerce supremacy. But the battle won't happen here in the States. It will happen in India. On Wednesday, the retail giant inked a $16 billion deal to buy a 77 percent stake in Flipkart, India's premiere online retail startup. And it's a move directly aimed at Amazon. Walmart is still America's dominant brick-and-mortar retailer (there's a Walmart within 10 miles of 90 percent of the United States population).