As freelance and in-house designer, I've used Illustrator extensively to make ads, marketing graphics, and...you know...illustrations.
In my recent in-house work we utilized two rendering styles for different applications:
In-situ example of a series of vector portraits.
Close up example of a vector portrait of the Soultanz, a musical duo.
In-situ example of a vector portrait.
Click to view larger: in-situ examples of calligraphic vector portraits, in-house
Vector illustration depicting the value of print advertising in theatre programs, in-house
A landing page dancer, in-house
The Bard, in-house
I've also used vectors on freelance work.
American Rage, corporate commission
Guest Performer, community commission
Arnold Palmer and Watermelon, corporate commission