Pros: many uses, cats LOVE it, only one ingredient, good for training
Cons: expensive, but buy the dog kind and it's cheaper!
My cats LOVE Purebites freeze-dried chicken. They go bonkers when I bring out the bag. If I don't lock the bag away in a drawer, they will rip the bag to shreds to get to the pieces. I love that it's only one ingredient: chicken.
Apart from giving as treats, it's good to entice cats to eat wet food instead of dry. You can crumble some on the wet food to get them to eat it. During playtime, I throw pieces around the room for them to hunt them down.
Tip: Buy the dog Purebites chicken, it's cheaper per oz!