We are using URL Shortener during our daily routines, even sometimes we don't need to short a URL because some web services do it automatically. For example, twitter is now shortening the pasted urls. People are feeling hesitation to use url shortener. This is because they think that there is no positive outcome through shorteners.
This is right that, using non-authoritative URL shortener will harm the SEO campaign. But well-behaved URL shortener are providing benefit. For example, goog.gl, bit.ly and youtube's url shortener are 301 permanent redirect which is a proper method to redirect. And permanent redirect transfer link juice.
