Most of the prior responses have listed many factors that may impact the response rate: letter, postcard, color of the piece, day mailed, frequency, hand written, or using an address label, etc.

I believe I still have the template for Georgia we used for Wholesale deals if you PM me I will send a white label copy. 

Should you not do anything with those deals or is being an entrepreneur more important than whatever label a bunch of people on an internet site want to argue about?

They at times also have the forwarding address printed on The return label when the forwarding address has expired.