Add a form on the website where a user can put in an e-mail and a message, and an e-mail will be sent to that user inviting them to Shadowcon. The invite e-mail will contain a referral code, of the same type as the ones we'd hand out on the cards. Ideally, it'd also have a link which contains the referral code, so if they click that they're taken straight to the registration page with the referral code already filled in.
Add a form on the website where a user can put in an e-mail and a message, and an e-mail will be sent to that user inviting them to Shadowcon. The invite e-mail will contain a referral code, of the same type as the ones we'd hand out on the cards. Ideally, it'd also have a link which contains the referral code, so if they click that they're taken straight to the registration page with the referral code already filled in.