URL shortening, and URL shortener services, are evolving rapidly into a real hype. And while they do make sense with Twitter (due to their 140 characters per tweet limitation), they are not all that harmless from a SEO perspective.
The most harmful thing when you use a shortener to link to your own site is: It is not you who gets the link love, but the URL shortener website. The same is true when other people link to your site via a shortener.
Now in the case of Twitter there is counter-value you receive: More space for your message.1 But I’m observing a trend to use shortened URL even in normal blogs / websites. There is even a growing number of plugins that help you automate their usage.
Why?
It is not because the shortened URL is more memorable (or would you be able to remember http://bit.ly/4CSWyR?)
Is it because it is “trendy”? Well, go on, fall for it if you must.
I can think of only one logical reason to use an URL shortener in the own blog: To cloak a link the target of which you don’t want to be immediately visible to the reader (an affiliate link, for example).
If your intention is to cloak a link, why not use link cloaking software instead. There is an excellent free link cloaker for WordPress from White Shadow. (He even provides a much extended premium link cloaker with many more features.)
And if you must have short URLs, check out a URL masking solution that creates short URLs on your own domain, like the Kael.me URL Shortener plugin for WordPress.
Cheers and happy URL masking. 
- And you need that space, because everything is part of the message, even tags. [↩]
November 23rd, 2009 at 4:13 pm
This is why I prefer to use my own short URL (the ‘ugly’ URL) for WordPress and Twitter. Keeps MY branding.
January 29th, 2010 at 6:38 am
I think you bring up some valid points and a decent solution. The comment:
“I can think of only one logical reason to use an URL shortener in the own blog: To cloak a link the target of which you don’t want to be immediately visible to the reader (an affiliate link, for example).”
I would tend to agree with this only as a partial demographic. Outside of limited 140 char sets for a Twitter entry, I personally shorten for one of two purposes:
1) in order to allow the end user to easily transcribe from mobile device to workstation browsers
2) in order to avoid a line break in a link sent via email, where the end user is too confused to understand the issue of the ‘broken link’
I also think that a URL shortening service is a way to hide the originating URL server, but for me, I do not use them to hide.
January 31st, 2010 at 11:23 am
Hello Ari,
good points. You may be interested in a “personal” shortener then. They provide a short URL path, but start at your own domain. So instead of “thingly.me/b17fe8″ your get “yourdoman.com/b17fe8″. Of course, if your domain is longish by itself, the shortening will be less effective.