Why use URL shorteners?
If you've ever tried to post a link to a Google map location, you know what URL shorteners are for. Here's the link to Bourbon Street, in New Orleans, LA: https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=bourbon+street,+new+orleans,+la&sll=30.083355,-90.068665&sspn=1.036192,1.408997&ie=UTF8&ll=29.964899,-90.063&spn=0.03242,0.044031&z=14&iwloc=A
If you don't have the patience to count, that's 202 characters. After using url shortener https://bit.ly, it looks like this: https://bit.ly/13whiJ…pared down to 20 characters. Pretty handy when you're twittering, trying to send a text message, posting a response with a character limit, or sending an email that will break it into manageable but useless smaller chunks.
The down side
The first thing you should notice is the anonymity. Even if you hover over the shortened URL, you don't know where you're really going, which makes you an easy target for spammers and malicious sites. More than once, I've clicked on tweets that had an interesting tag and a shortened URL that led to an affiliate marketing site that had nothing whatsoever to do with the content of the tweet. From a user standpoint, this represents unknown dangers, which can be significant for the uneducated, and unprotected, casual web user. In addition, there's always the possibility of hijacking if the url shortener service decides to try and make money from your clicks by adding an advertisement between your URL and the destination. So far, that hasn't happened, but it could. They can also be used to track user movements across the web. Maybe it sounds paranoid, but ad networks can already do it, so why not?
Another consideration is the value of linkbacks. Linkbacks are valuable SEO currency that help bring a website to the top of the search page. Url shorteners turn golden linkbacks into mush. No matter how many people click, the originating website doesn't get the credit. It also makes tracking down original sources more difficult, especially if the link becomes corrupted or broken.
The last thing to consider is the added layer of transit in the chain of communication. It makes the underpinnings of the link structure that much more complicated with an additional lookup operation.
On the other hand…
On the plus side, in addition to the obvious benefits of a shorter URL, many of the url shortener services provide user data that can tell a web owner where the clicks originate and the location of the user, and more valuable consumer data.
Good or bad, URL shorteners will be necessary as long as we continue to text, tweet, chat, fill out forms and argue the toss in the comment sections of blog posts.