I mean, Walmart almost certainly do track everyone's movement around their stores to see how to improve their conversion rates.
When I worked for UK financial company we would track how far people were going through our form wizard to see where the paint points were. The personal information never left the web page, but it would report back telemetry telling us how many people dropped out at each stage. That helped us to do split testing, e.g. does this label make more people fill out the form, etc.
