Eyes are fixed on retail giants Walmart Inc (NYSE:WMT), Lowe’s Companies Inc (NYSE:LOW), Target Corp (NYSE:TGT), Costco Wholesale Corporation (NASDAQ:COST) and others who are set to set to release earnings this spring. Foot traffic data could provide a glimpse into the sector’s upcoming performance. Walmart and Sam’s Club Foot Traffic: According to Placer.ai, visits at Walmart were up 3.9% year-over-year, and at subsidiary Sam's Club they were up 6.1%. Walmart's year-over-year visits fell 2.7% in April, rose 7.7% in March and rose 4.4% in ...