"He that has once done you a kindness will be more ready to do you another than he whom you yourself have obliged."
So... when you help someone, you tend to like them more. Take a nice, soft moment and think about that. Who have you befriended before? What do you think about them now? It's so true.
I think it boils down to the fact you are accepted. You dare to step outside of your ruts and reach out to someone. You've let your guard down.
When they accept your hospitality, they've complimented you, accepted you, endorsed your decision. So it's safe to help again.
You've also reached a common ground. You have something the other person needs, and you reach a mid-point where you can shake hands and make something right. It's almost a personal contract between two people.
1) Buy a book
2) Leave a review
3) Recommend the book to others
4) Write the author and thank him or her for writing the book
I can honestly say that I remember those readers who've reached out to me and complimented me on Lowcountry Bribe or FundsforWriters. Not sure who's helping who in this regard, but the symbiotic relationship works.
Those who email me, leave reviews, leave messages on Facebook, and Tweet back and forth with me are, in my eyes, charitable people helping me to remain a writer, become a better writer.
I've helped them in my own small way, and the fact they responded favorably to my effort makes me love them dearly. So I want to help them more.
From the reader's angle, they've helped me, and can see how their support has enabled me in so many ways, and they want to help me more.
It's why I leave reviews on Amazon and Goodreads. Someone helped me with his words and needs my help to become a success. I'm glad to help.
Yeah, confusing at moments, but guess what? It works. It's basically asking for help, getting it, and the giver makes a connection he wants to preserve. He "gets" what the other person needs, and loves being able to provide assistance.
That has to give you a warm and fuzzy feeling.