I have heard many dialogues that discuss the effectiveness of postcards, yellow letters, and bandit signs. 

A lot of people analyze their stance on these different tools to finding motivated sellers through the use of statistics and numbers. 

But generally, human psychology is left out of the conversation. Sure, these marketing techniques are easy to scale and easy to read. It's a numbers game right? 

But what is the most effective tool in regards to making the seller tick. Bringing the seller to make that phone call. 

How can you use psychology to your advantage when choosing the right marketing campaign. 

Does it vary by region? by sellers lists? or by any other variable?

(For example I have heard of someone posting a picture of themselves on the back of their postcards, slightly dressed down, with their dog and their family to point out that they are not a bank or some rich investor, but a nice guy down the street)