If you were interested in sending a list of ideas to someone for Father's Day, or for any other event, you can send a list of specific things to get like the original Star Wars trilogy DVD set, the link to the item where they can actually buy it like http://www.amazon.com/Trilogy-Empire-Strikes-Return-Widescreen/dp/B00003CXCT/ref=sr_1_1?ie=UTF8&qid=1464624984&sr=8-1&keywords=Star+Wars+dvd+set, or you can provide the person with a short link to the specific item like http://amzn.to/1TSMKtX.
The latter choice isn't something easy to remember but it is certainly shorter to type. Why use short URLs? Besides being shorter than regular URLs, there are at least two other reasons to use them. The first is for tracking purposes. Whether you know it or not, when you click on a link in an email sent to you from a commercial company, that click is tracked. The company is doing an email campaign and they want to know clickthrough rates (CTR). Most companies are happy with a 2% return. They certainly want more, but shouldn't expect it. Clickthrough rates on display ads is even lower than emails. But the clicks can be tracked through shortened URLs.
The second big reason people use shortened URLs is to hide the real destination. Spammers certainly want to track when you click on links, but they certainly don't want to tell you where you're going. This is so true if they're trying to take advantage of a browser exploit to try to get you to install some adware on your system, or any other inappropriate software.
How then do you know if it is okay to click on that shortened URL? While you should never click on links from total strangers trying to sell you the Brooklyn Bridge, a get rich quick scheme to send you a check where you have to return just half, or some other hair brained scheme to scam you out of your money, you might occasionally get a shortened link from someone you know. If their account was hacked, you shouldn't click on the link. But, how do you know?
If you're just not sure about a link, the best way to find out if it is okay to click/follow is to expand the URL without actually visiting the site from your server. The from a different server part is important as it doesn't expose your computer system / mobile phone to a potentially harmful site. The expansion of the URL will still trigger the tracking mechanism, but by using a site like CheckShortURL or Unshorten.it, you'll see what the underlying URL actually is. Some URL shortening sites, like https://goo.gl/ even let ANYONE see the statistics behind the URLs that were shortened by their service.
Is it safe to click on that link? Unshortening the URL will certainly help, but even after unshortening, you still need to be careful. If a URL is something like amazon.com.example.foobar, the link certainly isn't safe to click. Sure, it has amazon.com in the URL, but it isn't the Amazon site you would be visiting. Treat carefully and don't just click on links you get from someone.
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