Face charts are something a makeup counter does to help you remember what was talked about and used on you during your consultation. It is yours to bring home, products are written down and often colors are in the spaces for eyes, lips and cheeks to jog your memory. The face chart serves two purposes: 1. For your reference and 2. For the Makeup Artist turned Salesperson to also "refresh" your memory and entice you to buy.
I honestly don't use them on a regular basis when I work in store, unless I feel it will really help the person I am working with.
Bottom line: are the face charts helpful to you or are they just a bothersome clutter you have to take home after your visit to a makeup counter?