you know that...
...a long url can have over 1000 characters
...the short url will look like this (max. 22 characters) http://url4u.co/15FTGg or even url4u.co/15FTGg (15 characters)
...it checks if url is a true url
...a shorter url is usefull for posting in email, forums, social networks,... and it's easier to keep it in mind
...you can check your stats when you add a '+' character at the end of the short url (e.g. http://url4u.co/15FTGg+ )