Matt Turcutto I think your getting discouraged way too soon. I don't know if you have read the book "Real Estate Rehab Investing Bible" during your analysis period, but there is a good chapter in there about direct mail. One thing that sticks out is mailing campaigns run at least 6 months, doing a mailing once a month with each list. Which means you don't know if a campaign is bad, until you finish the campaign.
Also, before you start a campaign, figure out your budget, and mail accordingly. If you have $1200 campaign budget, you have $200 /mo to spend on post cards or letters.
It also looks like you want to change your focus after the second month. In a podcast with Sam Craven, I believe, he also did a campaign and got some good leads and changed something after month 2 and the calls stopped, so he changed it back and the calls came in again. Someone correct me if I'm wrong, but his regret was not running the campaign all the way, or tweaking it too much too soon.
I also would add the point of doing direct mail is getting your mail piece in front of the right people at the right time. Someone who is distressed will see your letter every month, but not do anything until their circumstances change. That could be month 4, 6, or 11 of a campaign.
I'm sure that there are way better experts here that can elaborate.