many are on yellow letters  many are post cards.. a lot are in handwriting with handwriting machines.. and the public frankly they fall for it.. but most of these folks are just not familiar with how things work in the industry..

Their mailbox was full of postcards and letters from other investors and we got the deal because we were the only ones that helped them find and rent a new place to live, which they cared about way more than the equity they were losing (they were 2 weeks away from losing it anyway, btw).  

I am thinking about starting off with a postcard and a newspaper ad and AM radio spots.  

The homeowner called me August, 2015 from a handwritten yellow letter I mailed him in November, 2014 and a postcard in January 2015.  

I've had sellers contact me via website off the postcard.

You can certainly use these for any niche, but they are more costly.For all the other niches other than probates I have found that postcards work just as well in my market.

I took a similar to what you mentioned because our budget is similar in my most recent marketing campaign, but I did a bi-weekly schedule; yellow letter, 2 weeks later postcard, 2 weeks later yellow letter, post card 2 weeks later, and I did this over the course of 2mos; spent about $2,700 total for the list and mail outs.

The goal for my marketing campaign is 3mos, and I want to switch to postcards on my next mailing to see what type of results I get.

Also, there is a lot of talk about using different direct mail campaigns like small text pc, yellow letter, professional letter, large post cards, zip letters, greeting cards, etc.

Starting with a postcard as the first mailer to save a little on the front end to weed out the undeliverables.