Machiavellianism!

People like to be deceived. White lies make lives easier. Sometimes, it can get so bad that when someone asks, "Do I look good in (insert outfit)?", they really expect you to say "Yes" or something positive. And that's even if they look so-so or even slightly bad in them. I guess they'd take it better if they looked downright awful in the outfit, but I somehow doubt that.

In fact, it has been found that people who know when to lie, and are able to conceal the fact that they're lying, get ahead in life better than those who can't! How about that. Gratuitous praise and pandering do help, and that's even when people are aware of it.

It's hardwired into the human psyche to appreciate praise, apparently.