How Does premium link Generators work?

Premium link generators have premium accounts on file hosting sites or someone donate premium accounts to these site for using to other users of the site.

How this procedure works?

When you insert your link to download your file from these sites, these sites download your file to their own server from the filehosting server that you inserted using premium account and serve the file via their server link to you or downloader.

Example:

https://www.rapidshare.com/files/1265731086/DC2E_BS.7z

By using a premium link generator:

 http://www.some-link-generator.com/file/DC2E_BS.7z

This link can now be downloaded directly without waiting time which is usually tolerated by free users when downloading the original link from the file host.
Sometime it can be resume able  unlike the original file host downloading restrictions.