What makes some products so engaging while others flop? Nir Eyal explains the psychology behind the world's most habit-forming technologies and provides practical advice for increasing user engagement. Nir is the author of "Hooked: How To Build Habit Forming Products" - Nir has been writing about the application of psychology to product design for many years. His work is often cited by top thinkers in technology, and this talk provides a useful framework for thinking about engagement.