A good way to market it using bounced emails. What I mean is make a email address using google, yahoo. Join as many ffa sites, blaster programs, etc and use that email address. Only Join Free Ones.
Put that email address on vacation mode with a message stating something like" Thank You for your email, I am currently on vacation but I thought you may find this site interesting". Then put your GDI link in it. Make sure your message is ok per GDI policy.
When someone emails you there offer they will get a autoresponser stating that you are on vacation with your little note.
That way it cost you nothing and you may get a few signups.
I hope this helps someone.
Scott