Walmart is still the world’s largest retailer, but a recent company memo highlights its struggles to overcome competitors like Amazon, Instacart, and Target. The document also hints at challenges the company’s new subscription service Walmart+ is facing in retaining new members. The 100-page document from February, which was viewed by Recode, was created for advertising agencies that Walmart invited to compete to handle the planning and buying of ad placements for the retail giant. The memo makes several blunt assessments about the uphill battle Walmart faces to hold onto its once-dominant retail market position, including in the US grocery industry, where the company has long been No. 1 in sales. Read more at Vox.