Walmart (NYSE:WMT) reports earnings on Aug. 15. Its results are expected to be decent, if not spectacular. Most analysts see same-store sales growth with operating margins nearing double digits, which should be good for Walmart stock. I’m not one to focus too closely on quarterly reports, opting to think bigger picture, longer-term. There are three things that I’ll continue to look for as the company continues to grow its behemoth business model. For me, it boils down to Walmart’s growing ad business, the u ...