I didn't until I started stealing my room mates floss picks last year.
I buy my own now and use them when I remember, probably averaging out to every other day or every couple of days, but I'm getting close to daily. I hated string floss and always found it too much of a hassle (getting the right length, wrapping it around your fingers and maneuvering it around) but the pre-threaded floss picks are amazing! It's actually kind of fun, I just do it while I'm watching tv or something. And the pick at the end is great too because I have a permananet retainer on the back of my bottom teeth and I can't be bothered to use those "floss threaders" to get underneath it.