Please help my direct mail!

[Mark Redmann]

Ok folks, so I have been mailing a postcard to just over 1900 addresses.  I have mailed 3 times so far with about 5 weeks in between each mailing.  The list I am using is from list source.  I am targeting absentee owners with some other factors to narrow down my list.  After reading a post by Michael Quarles, I applied what he said to use to narrow down my list.  

For the first 2 mailings, I was getting calls from people to remove me from my list.  2 weeks after my third mailing, I have received ZERO calls. I have already purchased enough cards to do 6 full mailings.  I know everyone says to stick it out for at least that, and that the "magic" happens in the 4th, 5th, 6th mailings.  I bought enough at the beginning because it was a better price to buy more and to commit myself to mailing at least 6 touches.

I get a lot of returned cards that say "attempted not known", "Not deliverable as addressed", "insufficient address", and "vacant".  I am saving all the returned ones, because in my mind vacant is a good thing.  However, if I was mailing to absentee owners, why would their house be vacant!  Shouldn't the owner be living there?!  in any case I want to follow up with the vacant ones for sure.  How do I do that?  Where should I start?  If the address I originally obtained for the absentee owner is now vacant, how do I find them?  

What would you do? Thank you!!