I recently had a motivated seller respond to my postcard 2 days ago.

I used an ugly yellow postcard 4" x 5.5" glossy front, sent with a regular postcard stamp (not bulk !!)

I got a call today from an ugly yellow postcard 4" x 5.5" sent with a regular postcard stamp (not bulk) I bought 10,000 post cards for $500 at Vista Print.

A couple of years ago I sent out 5,000 professionally designed color postcards 8" x 5".

However, I think there is a lot of rah-rah which works to keep you going for a couple weeks without any real problem solving skills.I think I'd rather call up one of those postcards ("WE BUY YOUR HOUSE IN ANY CONDITION - EVEN WITH DEAD BODIES) and ask them you'd like to apprentice to them.  

I am thinking about sending postcard size yellow letters to see if anyone wants to sell.

Or postcards? 

Cold calling yourself is the equivalent to handwriting postcards yourself.

This one responded to a stupid, ugly, yellow postcard.

Alternatives (expensive, but they work sometimes) include SMS & Postcards.