Your app makes me fat is such a great post about respecting users by Kathy Sierra:

That one new feature you added? That sparkly, Techcrunchable, awesome feature? What did it cost your user? If the result of your work consumes someone’s cognitive resources, they can’t use those resources for other things that truly, deeply matter. This is NOT about consuming their time and attention while they’re using your app. This is about draining their ability for logical thinking, problem-solving, and willpower after the clicking/swiping/gesturing is done. 

It reminds me of Paul Ford’s admonition in 10 Timeframes:

If we are going to ask people, in the form of our products, in the form of the things we make, to spend their heartbeats on us, on our ideas, how can we be sure, far more sure than we are now, that they spend those heartbeats wisely?

We are responsible — at least in part — for how people spend their time. We shouldn’t take that lightly.