These are incredibly useful. I use them to attach various toys to my baby's swing, carseat, etc. I use them in temple attached to a toy so that when he drops it, the toy doesn't fall to the floor and I just reel it back in. He even loves the rings without any other toys, and will endlessly chew on them.

That said, I bought this exact same product in my local Target for $4.99. Not on sale either.

Update: When I wrote this review these were selling on amazon for more than $15! It seems the price here has become more reasonable.