I want to give my email list a shot in the arm by running a referral competition. The idea is that I'll send an email to my list and ask them to refer X number of friends by filling in their mate's email addresses on a form on my site. Everyone they refer then gets an email inviting them to subscribe to my list. I'll then choose someone at random to win a prize. I've had a look are ounce and haven't found any plugins for running this sort of referral system. Am I overthinking it? i use Aweber for managing my list.