Instead of using, for example: http://primaryposition.blogspot.com/2011/01/seo-and-internet-marketing-training-and.html , you can shorten it to this http://goo.gl/RIcAV. This URL is much easier and shorter to share in places like twitter, linkedin and facebook where space is limited - or on e-mail where it can get concatenated and stop working (if the URL isn't whole, it mightn't take the user to the desired spot).
Essentially all that happens is that Google have purchased GOO.GL - a play on "Google". GL is the ccTLD (Country Code Top Level Domain - ccTLD) for Greenland. This software then translates the short address into the long address, and also provides a fast lookup so that sites can show the target URL when you mouseover
It also gives amazing real time stats about how many people follow your link, when they clicked and from what country and platform.The shortener can be used without logging in - handy but then it doesn't store any details. As per usual with web visitor stats, the information tracked is not personal and doesn't identify any individuals at all.
The main dashboard gives you an overview of the URL's you've shortened
This makes it very handy when sharing on twitter - so you can see who finds which links interesting (by country) and how many people following you are actually engaging with you. This should hopefully improve your blogging and tweeting content!SimplyZesty blogged about tracking twitter RT Click-through-Rates here, which I thought was interesting and relevant.