One of them being an extremely long tail of assortment that typically carries good margins with it. Walmart continues to snap up pure-play category-specific e-commerce retailers like Bonobos (men's clothing), ModCloth (women's clothing), Shoebuy (shoes), and Moosejaw (outdoor). The leadership of these startups then become the category managers of those specific categories for all e-commerce platforms that Walmart owns (including walmart.com).

If I were a betting man, I would guess Walmart is looking at additional acquisitions of pure-play e-commerce players in home goods (Wayfair maybe? though it may be a little too pricey), automotive, toys, OTC/Rx, office supplies, etc. These categories would be prioritized by what already has the largest e-commerce volume.