Lousy article. Where's the "because it's in their best interest" option? Sometimes people say yes because they think they're getting a good deal, not because you've used psuedo-psychology to twist their arm.
People do act rationally. But it's a small minority of the time!
Okay, that's a bit of an exaggeration. We tend to act rationally a lot of the time. But those are often "no brainer" situations where there is little question about the best option. The 6 factors in the article come in to play when decisions are less clear.
