.PRO is a top level domain, owned by RegistryPro, owned by Hostway (as far as I know). It was/is intended for professional use, and requires anyone that registers one or more for themselves to provide professional or corporate documentation in order to activate and retain the names.
Because of the exclusivity, I have noticed an abundance of available keywords for this extension. In fact, because of the quality of keywords available, I couldn't help but snatch a few up myself.
Regardless, this topic was created to get your opinion on it.
If you already own one (or some) yourself, please feel free to share them. If you don't own any, your two cents are still very much appreciated.