Along with the issues above, and the obvious lack of brand recognition, there’s also a concern that URL shortening services may stop working without warning. The popular tr.im closed down recently, saying there’s no way for them “to monetize URL shortening — users won’t pay for it”. They’re back now, but for how long? Meanwhile, others may disappear without any explanation — and their domains expire, they’ll be taken over by SEO bandits or malware distributors. Any shortened URL you registered with their site will be controlled by someone else.