Even though the common stereotypes for PR is to distribute your story -- it is also a great way for experts to find other experts to voice their opinion or strengthen their point.
Just as you'll often times take interviews or cite quotes from the elite in your niche, press releases are a great way to put you on the radar as one of those elite.
In the end, it is all about brand image. Any time you are cited, used, or written about, your brand equity goes way up!