Some advertorials contain no-follow links & are appropriately labeled as Google has requested and yes, I have seen them. But in my experience, they get much less attention.
Lately when I am asked to look at an advertorial, 99% of the time is is an advertorial that has a do-follow link. Those are the advertorials people are much more likely to spend big money on & get big ranking boosts from. When I reverse engineer backlinks, I discover advertorials with do-follow links. This is just my personal experience.
I'm sure there are many advertorials with no-follow links but they just don't come across my desk.