This is a great read. At first the idea might seem terrible, but if you apply it to a mostly business-related perspective I think it works well.
Also, as much as I hate to say it, I think there are enough people out who are happy to take advantage of others’ time such that this article is warranted. I usually try and go out of my way to help friends, but I have cut back on what I’m willing to do for others. I think it has been beneficial for my own mental health.