The difference between saying something and actually doing it 

About a quarter of the time I take Ubers here in Delhi the driver asks me, when I get out, to give him a five-star rating. (Drivers must maintain a certain rating to ensure they can continue working on the platform.)

Usually I just nod my head and say “yeah okay,” and proceed to give them whatever score I would have given them anyway. 

The other day a driver did something different. 

As I was getting out of the car he said “sir” to get my attention, then pointed at his phone, where he had selected five stars in his rating for me

Then when he saw I was looking, he pressed submit.

When it came time for me to score him later, I also gave him a similar rating. 

He was a good driver indeed, but he also understood the law of reciprocity. He knew the difference between just saying something and actually taking action. And that I may well feel inclined to help him out too (since riders are also ranked). 

Clever.