I've been thinking about this as well as I'm currently determining if I should go drive through only, standard walk in, or possibly a mobile truck.
For convenience sake, if I go for a walk in, I am considering a 'fast lane' type set up. I've seen places that have rewards cards that you can load up and do a pre-paid type setup. This would allow for customers to pay rapidly and load up the card on-line. You could even set up a special counter for these people so they won't have to wait too long.
So much has changed over the years. Social Media (as we know it) wasn't around nineteen years ago. People had to get creative in order to attract customers to their businesses.
I remember when it was popular for local restaurants to send other businesses (offices, stores, etc.) a fax every morning that listed their daily lunch specials. Now, many of them post their menus on Facebook. Things have certainly changed over the years.