Yeah. Desktop virt for developers and QA is certainly visible.
Virtualized server farms, OTOH, are transparent. You could be logging into a VM and never know unless you ran dmidecode (Linux) or Get_WMIObject Vendor (Windows, IIRC).
That VM could also be moving from one physical machine to another while you're logged into it. You'd never know.
Last project I worked on was at a bank, with a few hundred VMs used to replicate the prod environment about 18 times. Project budget was $450M AU, about $400M US. VMware got a good chunk of that.
As far as I know, desktop virtualization (for developers and QA) is a large chunk of VMware's business, indeed it's where they got their start.