When services like Twitter limit your messages to 140 characters, you don't want to waste 50 characters on a long URL (e.g. http://news.ycombinator.com/item?id=

When services like Twitter limit your messages to 140 characters, you don't want to waste 50 characters on a long URL (e.g. http://news.ycombinator.com/item?id=2547123 http://news.ycombinator.com/item?id=2547123) when instead you could create a short(er) 10 character URL instead using a service like bit.ly, etc.