Most of the times we hear design for engagement or for better user experiences. Why don’t we design for happiness? Who is interested in happy users? I will give various examples of games and websites whose success depends on many things but joy and pleasure. Probably the key is in their information architecture and consequently in their interaction design. We as designers have an enormous responsibility for users’ behaviours. How much aware are we of our designs implications? And how much are the users? To me, happiness in UX is the absence of frustration. Let's fight 'dark patterns' to make a more free Internet. If you want to learn about Dark Patterns: www.darkpatterns.org