Are drive-thru lanes worth the investment for convenience stores?

From In-N-Out Burger to Starbucks and McDonald's, some of the most popular restaurant chains in the U.S. have mastered the art of drive-thru service and credit it as a key factor in their success. Chick-fil-A does around 60% of its sales through its renowned drive-thru lanes, while at McDonald's that figure is around 70%.