Walmart is pushing harder into advertising with a new tool that shows if people buy a product after seeing an ad for it

· Walmart is rolling out a measurement tool to all of its advertisers that shows how online ads drive in-store and e-commerce sales.
· The retailer says the tool is its first step towards building an ad manager akin to the technology that advertisers use to buy ads on Amazon, Facebook, and Google.
· Walmart is also eyeing a...