Reciprocty is an old-principle - the ol' give and take.
Yet it's very powerful.
One that's rooted in evolution. Across animals and humans.
Let me tell you a story. In the human domain for now.
The Hare Krishna Society is a religious community with its roots in India. They dressed in saffron robes and applied powder on thier foreheads and stuff like that.
So when they moved to America, naturally American citizens did not feel drawn to the HKS.
It was not good news for the HKS though. They needed donations to keep themselves afloat.
So they devised a strategy - they waited in airports and handed out the Gita ( religious Hindu scripture) to passerbys as a gift. Either they would receive it graciously or they would be reluctant to accept it.
In either case, the HKS members made sure that the passerby received his "gift".
Once that was done, they asked for a donation.
And it worked wonders. They raised millions in donations this way.
Reciprocity is powerful. It puts the other person in your debt.
It's why I'm writing this to you. To put you in my debt.
But people offer free value for this reason.
Even KP, the build in public guy said "Give 100s of times. Ask once".
Classic example of reciprocity.
Pretty powerful stuff right?