It was previously called the removed from game zone, which does make clear what its meant to be used for
Upgrades: Swap out less efficient dinosaurs for powerhouse threats like (a perfect new commander for the deck), , or
In a format that has multiple copies of ritual effects such as Dark Ritual and Cabal Ritual while paired with Demonic Tutor to fetch for it, it's easy to see why its a very solid strategy
Equipment was the big smash hit from this set, and went on to become an evergreen mechanic, being a major theme to Zendikar rising and to the upcoming Kaldheim set to name a few
My favorite part of Puppeteer Clique is exiling the creature at end of turn
That said, you can also find people who need quick cash or are simply tired of keeping their money tied up in a position, which in turn can lead to a solid deal for you