perm.ly is a free service that helps you to organize your links. 404s are history. Permanent URLs or Permalinks means that you can make sure your shared URLs will lead to the right target, even if the original target page has been moved. We have prepared some comics to explain use-cases in more detail.
You can track the click count of links that you have shared in social media networks, connect it with your Analytics account and even track downloads easily without any technical effort.