Six reasons why things catch on or become contagious?

A discussion based on a book called “Contagious” by Jonah Berger, published in 2013. A quick summary of the topics covered in the book and what I will talk about: Social currency - does it make me look good? Triggers - how are you reminded of the product? Emotion - strong emotions = sharing Public - what is everyone else doing? Practical value - is it actually helpful? Stories - is my idea/ product a relevant part of a cool story?