Star Power- it makes you famous and people are impressed when they meet someone on TV. As silly as that may seem your clients will see you as bigger then life and you may just out shine your competition.
You’ll know if your getting response by the amount of strangers who call you by your name or say a phase from your commercial. Most people won't tell you they saw your commerial otherwise.
It helps your customers know and trust you before they even step in the door.