Once you are aware of this, you see it pop up in old episodes in weird places.
In the "Koi Pond" episode, Andy and Pam are look at an office directory sign, and Andy tries to sing a song using the directory as lyrics. The camera focuses on the directory, and in Suite 204 of the Wilkes-Barre Industrial Park... Utz Quality Foods.
The other place you see it subtly is the vending machine in the break room. There are usually bags of Utz chips in the top row, so you will see them over a character's shoulder.
The most prominent usage has been Utz Cheese Balls - the Michael Scott Paper Company played a game with them, and in "PDA" there's this scene:
