I've gotten two mystery items so far, and both widely exceeded what I paid for them in value. These are not leftovers!
One was a Mantra glass bottle, which would not have occurred to me to buy, but quickly became one of my favorites. It is really nice! And they seem to have a magical ability to select the right color.
The other one is an insulated stainless bottle. It was apparently an older model, cylindrical rather than tapered, but I actually like it better. It has become my road cup, and I love it.
This is just one of many things to like about a quirky but excellent company.