Nir’s Note: This article is adapted from Hooked: A Guide to Building Habit-Forming Products, a book I wrote with Ryan Hoover and originally appeared on TechCrunch.

Earlier this month, Twitter co-founder Biz Stone unveiled his mysterious startup Jelly. The question-and-answer app was met with a mix of criticism and head scratching. Tech-watchers asked if the world really needed another Q&A service.

You can read the Nir and Far blog post on: You'd Be Surprised By What Really Motivates Users https://www.nirandfar.com/2014/02/youd-be-surprised.html

Nir & Far, a podcast about business, behaviour and the brain by Nir Eyal. If you enjoy this podcast, please subscribe on iTunes and leave an iTunes review. It will greatly help new listeners discover the show. Please visit my website Nir and Far for other info about my writing, books and teaching: http://www.nirandfar.com/