Twitter messages are limited to 140 characters. If someone mentions a URL in a Twitter message a lot of the available characters are already taken. To overcome this problem, Twitter in its web interface for creating messages converts sometimes long URLs into TinyURLs. In a TinyURL, the "long" URL is being replaced by a shorter URL of the form http://tinyurl.com/?????? where ?????? Is an automatically generated combination of letters and digits. Besides TinyURL there are other URL shortening services available. Twitteriffic also uses TinyURL. Twitteroo used to generate urltea.com URLs, but recently it has implemented rurl.org.
According to Google, these are the most popular URL shortening services used on Twitter.com.
Very often used
TinyURL.com - references
Sometimes used (more than 1000 references found)
urltea.com - references
snipurl.com - references
Occassionaly used (between 100 and 1000 references found)
rurl.org - references
tweetl.com - references
dwarfurl.com - references
Exceptionally used (between 10 and 100 references found)
urlx.org - references
kurl.nl - references
tinypic.com - references
shorl.com - references
Extremely rarely used (less than 10 references found)
digbig.com - references
snurl.com - references
Some of the other URL shortening services offer extras compared to TinyURL.
- a shorter URL (unfortunately only a few characters less)
- click stats : how often is the link clicked
- some degree of customisation for the generated URL
- guaranteed ad free.
- guaranteed no links to spam or porn sites
Why would someone use another URL shortening service instead of the default URL shortening service in the tool you are using while twittering ? Perhaps access to click through stats or a personal taste for one of these services perhaps combined with a dislike of the default service. Personally, I am a bit of lazy, so I am not going to invoke another service to convert a URL if Twitter (or one of the applications I am using to post and read Twitter messages) will do the job automatically for me.