The main reason for using shortened URLs on Twitter is to keep as much space as possible for your own insightful comments. That said, it would be good if the tool that shortened your URL added a bit of value, too.

Here are the four main reasons why I recently started using Bit.ly:
1. TinyURL’s declining popularity.
This may or may not be undeserved (your mileage may vary according to use) but there’s no denying that popular sentiment – driven by a combination of downtime, decaying links (linkrot), and the recent cross-site scripting attack that used TinyURL to spread its maliciousness (good explanation here) – regards TinyURL with increasing distaste.
I’ve not experienced problems with TinyURL myself but Bit.ly offers me things that TinyURL doesn’t supply off the bat.
2. Browser integration.
I use Firefox. You can install Bit.ly in your bookmarks toolbar and, when you want to shorten a site’s URL, simply click on the bookmarklet in the toolbar. Unlike TinyURL (also available to install into your Firefox bookmark toolbar), which always loaded its own page in place of the page I was viewing, Bit.ly opens a new tab and leaves me on the page I’m looking at. This seems to me to be eminently sensible.
3. Send directly to Twitter.
Better yet, when you go through to the Bit.ly page, you find that your shortened URL is sitting – along with the original page title – in a box perfectly suited for Twitter. When you register at Bit.ly, you can add your Twitter account details. The benefit of this is that you can then simply add your comment next to the shortened URL in the Bit.ly box and send it directly to Twitter. No need to cut and past the new URL into a tweet. Sweet.
4. Free stats.
Nobody likes to be ignored. Now you can see exactly how popular (or not) your suggestions for reading are among your Twitter followers. Bit.ly tracks how many clicks your shortened URLs get. This is not not simply an ego massager. For business accounts, this is a great way to test and measure where you can exert influence or show leadership. Of course, this means that the tweet relating to the shortened URL needs to be fairly explicit in defining what your followers are clicking on – which is good Twitter practice, in any case.
And, whether there is an element of ego massage or not, the stats actually encourage sharing. This has got to be a good thing. It’s great to be able to see that when you linked to the this story, people were clicking through at the rate of one a second, while this link inspired no visitors at all.
Let me know what URL shortening service you use – and why.

You missed one service Linkbee, which does really work for me. Apart from shortening URLs it lets you earn a small amount of money every time a user clicks a link.
I only missed a tool to quickly convert HTML with links and turn it into a format suitable for forum ad blog posts. The good news: there’s now an online tool which does just that.
See http://linkbee.com/linktools
Happy converting!
P.S. if you need to sign up with Linkbee please use this url: http://linkbee.com/28474
Very interesting. I’ve been using TinyURL from my browser (Firefox) mainly because it was the first one I knew.
I wasn’t aware of the added benefits of bit.ly. Might give it a try.
bit.ly now also shows the total number of times the url was clicked within the service (using your short url + others’)
Thanks, Shiju Alex – that feature seemed to appear as if by magic the day after I wrote the post! What I really like is that you can see how popular the link was before you tweet your own link, which gives you a sense of whether you’re contributing something unique or following a growing trend.
Yeah man, Linkbee rocks. Not sure why anyone talks about them?