Arguably, the activity does not always correlate with user happiness.<p>I don't want to be because of actively using the software. I want to be happy because the software solves some kind of problem, efficiently. There is fine difference.<p>Games: make me happy through the act of using them.<p>Accounting software: I don't want to be forced to use it constantly. My idea of happiness would be to get it done with as little effort on my part, as infrequently as possible.<p>Extreme example: LinkedIn requiring users to log in every month or be prioritized down in searches. That would increase how frequently users log in but I doubt anybody would agree that this would improve user happiness.