How did they know?

I've used the treadmill here at the apartment exercise room all of two times now and today I got a postcard from Target addressed to me personally (I checked) inviting me to "refresh your workout wardrobe..." How did they know?  Do they think my sloppy jeans and sweatshirts aren't classy enough? Who turned me in to the workout fashion police?  It will be a dark day in the gym, I mean black out dark, before I wear any of the skimpy outfits they are showing in the pictures in public.