The recipe book for the attention economy: Nir Eyal with Ryan Hoover (2014) teaching product builders the Hook Model, the loop that brings users back without paying for ads.
Trigger, action, variable reward, investment. Repeat until the product lives in “The Habit Zone”.
The pairing is what makes it interesting: Eyal later wrote Inmune a la distracción, the user-side antidote. Read together they’re the full anatomy of the hook, from the builder’s side and the defender’s side. Know the trick, respect the magician less.