Have you ever sat down and thought about all the places you take your phone? Such as the bathroom, the mall, the fair? All these places have tons of germs, and when you take your phone with you to these places, you get them dirty.
For example, let's say you take your phone with you to the bathroom. You might not mean to, but chances are you're getting E. coli on your phone. This is a germ that comes most commonly from poop.