The biggest competition for Wal-Mart (WMT) may not be other grocery chains like Fred Meyers or Costco, but online retailer Amazon (AMZN). Neil Ashe, chief executive of Wal-Mart's e-commerce unit, spoke on Tuesday about increasing their global online sales and making ordering through their website easier for their customers who are more and more on their smart phones while they shop. While he said Wal-Mart was on track to do over $9 billion in online sales this year, they're testing a new locker system that will hold goods ordered online that can be picked up by shoppers later. This is similar to Amazon's locker plan that is being set up in Staples Inc. stores.