You did sum up how one can build the right plot in a simplistic manner, plain enough for anyone grasp.
However, I believe, to a great extent, that what qualifies a book as bestseller is how well majority of its audience are able to relate with its theme(s). And I think one who desire to write a bestseller book must this.
Thanks @artguru for sharing this.
Aaah, yes. That's a point! How people relate to what they read.
Yip, people are inclined to put themselves in the shoes of the hero or heroine and how they would react to the circumstances of the plot !