URL shortening
The convenience offered by URL shortening also introduces potential problems, which have led to criticism of the use of these services. Short URLs, for example, will be subject to linkrot if the shortening service stops working; all URLs related to the service will become broken. It is a legitimate concern that many existing URL shortening services may not have a sustainable business model in the long term. In late 2009, the Internet Archive started the "301 Works" projects, together with twenty collaborating companies (initially), whose short URLs will be preserved by the project.