No, you can't use Google Analytics tags; the tags are generated by DojoMojo's system.
Each brand needs to make tracking links for each channel they're planning to promote the sweepstakes. In order to enter the giveaway, people need to follow one of those tagged links.
Don't worry, DojoMojo's generated link will track the source, medium and campaign name for you.
Only Hosts can track landing page traffic on Google Analytics.