Think analog watch/clock with lots of moving parts, the “works” of the clock.

What makes the customer tick?

Literally “how does the customer work”

In that sentence it really means “the customer will let you know what they want, just pay attention and listen”

RE:
What does tick mean in this sentence: Customers will tall you what makes them tick.?
Know success. Customers will tell you what makes them tick. Listen, then tell the team.

I once met a man with the ticking in his head who was screaming out “KILL THE VIPERS , KILL THE VIPERS” . He was under the impression an invasion of enemy aircraft was releasing bombs filled with poisonious snakes . He was screaming at the top of his lungs when all of a sudden an actual snake fell from a tree , landed on him , and we had to rush him to the hospital . It was horrid how he continued to scream . It was an hour before we had him calmed down . Now he is a “vegetable” in a mental ward . For the mental facility , this guy will be a good customer for years to come

For example, beer commercials geared towards twentysomething males typically appeal to their love of sports or chauvenistic leanings, while car commercials that target executives use images alluding to finer things and lifestyles, implying that their product is designed specifically for customers with discriminating taste.

For example, with a wind up watch, its all the gears inside that make it tick.

With people, most of the “gears” are more like thought, feelings and behavior.

It is derived from the old fashion wind up clocks. Knowing what makes a clock tick – means understanding the internal mechanism.