Short URLs, as provided for instance by TinyURL.com or MakeAShorterLink, are now commonly used when posting to newsgroups or mailinglists. These links are primarily used to get rid of the problem of wrapped URLs in many NNTP/Mail-Clients as well as to make the posts more readable.
Unfortunately, these links also provide a problem regarding future retrieval of information. Often, the short URLs are only valid for a certain amount of time, afterwards they cannot be resolved anymore. When searching newsgroups on the hunt of a problem, I sometimes come accross such invalid links. Nothing angers me more than when reading “just see http://xxx.xxx for the solution” and having no possibility to retrieve the information.
tinyurl promises on its front-page to create an URL that [...] will not break in email postings and never expires. Quite some challanging promise, isn’t it? makeashorterlink.com is more conservative in their promise, they only tell that it is going to last a very long time.
I do not want to say that these services are not senseful, on the contrarary, there are many cases where they are senseful. Long links in mails, postings, and instant messages are quite a pain sometimes, but the problem, especially in support forums and newsgroups is, that in my opinion the chances are higher that the short URL service will discontinue than that all archived postings will expire.
Of course, one could argue that the chances are as well that the real URL hidden by the short URL is not valid any more. This will also result in loss of information, without any doubt. If such a commonly used service is discontinued, a lot of URLs become invalid at once where the hidden URL is lost forever while the service behind it might still be available.
There is another point about the short URLs as well: I usually want to know where I am going before clicking a link. That’s also impossible with short URLs.
So, what to do about it? In my opinion, whoever wants to should continue using the services; I sometimes use them as well. But one should also add the long URLs at least to the end of an e-mail or a posting. They might be unclickable due to line breaks, but in case the short URL expires, it is still possible to reconstruct the link by hand.