I post a link to Grooveshark on Facebook like http://grooveshark.com/s/Toothpaste+Kisses/3gGocy?src=5
and get a seemingly normal result (link to another page) yet once clicked, it transforms into a Flash widget like this (the URL to the SWF is https://grooveshark.com/facebookWidget.swf?songID=249422).
My question is how is this achieved? I know you can add all sorts of special Open Graph data to a page but is this some kind of special deal the company has going on with Facebook? Can anyone illuminate this mystery because it would be very useful to understand. Thanks!