I only use "no contact" with a bird when she's disrespectful, like The_411 said (+rep, brothar!). The thing is, men don't know how to be men. What usually happens with guys is this: they see a girl, they like a girl, they pursue a girl. The girl eventually notices them, and if they've got their stuff together, the girl begins to like them. And here's where guys screw up. There's two different ways guys fail when they get the girl interested.
1) They go "No Contact" to get her MORE interested. Do you honestly not see how stupid that is? and 2) They go overboard with contact and start to look needy. Both situations end badly. Most guys need to realize that they got the girl interested in the first place by being themselves! Keep doing what you're doing man!
You can't really blame a guy for falling under option 2 mentioned above and going overboard with contact though, he just scored! He's excited! Most guys usually do this. I've been victim to this myself. When this happens, the women start to develop an evil sense of superiority. "Oh this guy really likes me a lot teehee!! Let's see what I can get away with!" ...and the disrespect begins. This is what most PUAs confuse with what they call "shit tests". They're not tests. Us men give women this false sense of superiority, we're to blame!
And here's where the real men shine through. A real man would obviously not accept any disrespect from a woman. For goodness' sake, she's a WOMAN! Which brings me back to the beginning of this post (funny how that worked out!): No contact is used to punish disrespect. If she doesn't respect you, she's not worthy of your attention and affection. It's something that's earned. I think it was Pook that put it so perfectly. "For if you stand for nothing, you shall fall for everything!"