What is the deal with ozone generators?

Like this one. Last time I checked, ozone was a pollutant. How can ozone generators help us if we can’t breathe it in?

A recent thread dealt with this.

As did an older one that was much more informative, that I couldn’t find in time to post to the other one.

I’m talking about ones that are actually meant to create ozone to purify the air. I saw an infomercial on one that criticized the Ionic Breeze. The one advertised used a fan to spread ozone throughout the room, and you could stay in the room while it did it.