Review (5/5): These actually work for thinner hair.
I have very, very thin hair that is just above hip length. These clips do stay in my hair, for the most part but I usually have to adjust the clip at least once during the day. No fault of the clip...it's the thin hair I was blessed with. They have a nice strong grip and seem sturdy enough. They are 100% cute and versatile.
I recommend these...especially if your hair isn't extremely thin like mine.