Report vs. mini-course
This is just a theory, but my guess is that you might have better success with an e-course autoresponder rather than giving away a free report.
For one, the freebie seekers download the report and opt-out or they just use a junk mail account to grab their report.
But by making them look forward to your next email, you have an opportunity to build a relationship while they develop the habit of opening your emails and start to recognize your name.
Anyone have any experience with testing the two formats out and the results?