Over a decade ago, I bought one of those Sharper Image ion air purifiers. I told all my friends how great it was - totally silent but really cleaned the air and left it with a fresh scent.

About a year later I started reading scientific assessments and reviews of it. It in fact did nothing to clean the air and the "fresh clean scent" it put out was potentially harmful ozone.

It was then I realized that I was as able to fall for marketing hype as much as anyone else. That made me much more wary.