We use a combination of yellow letters, typed professional letters, and postcards.

I found Virtual Wholesaling (.com) to be much more up my alley - using direct mail postcards and voicemail boxes instead of driving around neighborhoods and posting bandit signs."

I have heard of marketers reaching out to those individuals when the owner's address comes back as a RTS because of the address being vacant, unable to forward, or not deliverable as addressed.Can someone who follows up on these RTS leads tell me what you do with your postcards or yellow letters that get returned when the owner's address is vacant?  

At closing I joked that he had received 17 previous letters/post cards from us but had no recollection of them.

I love the postcards too.

We have added QR Codes to our yellow letters and postcards.

Glossy color post cards?

If that's the case, send a mailer (if you're planning on sending a letter/postcard) to the address that's listed for the owner in public records.

I'm aware that it's a smart idea to send out cheap postcards to find the return addresses for further investigation.

Also how does a greeting card differ from say a postcard?