But there is a problem in using these links in mobile browsers. Because they doesn't keep running javascript timeount function. They only able to run timeout when they are loading webpage.
However you can overcome this problem by using this simple trick: when your browser loads ad.ly link you will be able to see 'please wait..' text at the top right corner. Now, go to adress bar of your browser and type the following
javascript:
Press Go/OK/Done Now browser will again start loading but not reloading. During this time, timer will run and 'skip ad' button will appear. If not then again repeat the same. After that click on 'skip ad' button