The Positive Effects of Motion Blur

Its incredibly frustrating to be photographing important images only to have them turn out blurry. There's nothing more irritating then taking a photo of something cool and then realizing the photo is going to come out blurry because someone nudged you. Its equally annoying when trying to balance on one foot in order to take a cool shot when you lose your balance just as you click the camera. It would be better off if little annoyances like this which result in motion blur didn't exist.

Although motion blur is usually the result of an accident and can result in disappointing images, motion blur, if used correctly, can incredibly enhance an image. In an article titled "Move Your Camera to Create Motion Blur," the author writers about some of motion blur's positive effects. He says, "[a] purposeful camera shake can actually give an image a sense of movement, excitement and energy." Generally, while taking photos, one would want a camera to be secured to either a tripod or a monopod in order to reduce movement and blur. However, as the author emphasizes, blur can significantly add to a photo's mood. Blur can give a sense of life to an otherwise lifeless image.

http://digital-photography-school.com/blog/move-your-camera-to-create-motion-blur/