“The actual number is 7 percent. Not 47 percent, not 27 percent, but 7 percent. Research by the Keller Fay Group finds that only 7 percent of word of mouth happens online.
Most people are extremely surprised when they hear that number. “But that’s way too low,” they protest. “People spend a huge amount of time online!” And that’s true. People do spend a good bit of time online. Close to two hours a day by some estimates. But we forget that people also spend a lot of time offline. More than eight times as much, in fact. And that creates a lot more time for offline conversations.”

Contagious is a book I found out about in a way I'd never discovered a book: A rapper mentioned reading it. Nipsey Hussle mentioned the book after he sold a mixtape for $100 a couple years ago, referencing the $100 cheesesteak at a restaurant in Philadelphia.
I put Contagious on my list and just now got to it 18 months later.

Written by University of Pennsylvania professor Jonah Berger, Contagious is about deciphering what it is exactly that makes things catch on and blow up. Viral videos, a new restaurant, some stunt that happened on TV, a story that gets passed on through generations. Berger argues that none of this is luck -- there are certain principles in place that create this phenomena.

Contagious manages to share valuable information while not boring the reader to death with too much "academic talk". Berger continuously shares stories to illustrate his points and make them "sticky" i.e., easily memorable.

Contagious is a short read that makes it points and gets out of your way, followed by a series of group discussion exercises to see how well you were paying attention, and an extensive references section -- true to his college professor roots.