E-commerce giant Amazon is investing more than $4 billion to triple the size of its delivery network by 2026 with a focus on expanding delivery services across rural America. Tens of millions of U.S. customers in more than 4,000 smaller cities, towns and rural communities will get access to same-day and next-day delivery by the end of the year, the company announced on Tuesday. It's the latest development in its effort to ramp up shipping speeds and jockey for dominance against competitors like Walmart.AMAZ ...