Sending out a couple of letters or postcards isn't going to make life-changing money.

Postcards will go out quarterly.

Have house that requires a Cash Purchase.Have gotten many postcards.

Do I leave a message with this Ohio number when the postcard comes from Texas?

Making mailings is one way to find good deals, but the return on a mailing is very low and expensive.Doing a mailing campaign is a passive way to market for deals - If you want to accelerate your potential to make money in this business, I would suggest using active marketing ---Farming - looking for vacant, ugly houses - tracking down the sellers - make an offerSit in your local rent and housing court - no body wants to be there - great place to find burned out landlords who will be glad to discount their property to youExpired listing - these are sellers who have a property that did not sell - you can make their dream of selling a realality and profit at the same timeRather than licking stamps, designing silly yellow letters or post cards, stuffing envelops, buying postage, running to the post office or sitting home waiting for the phone to ring -- you'd be lot more successful by entering your market and doing peo-active marketing for the gold nuggets you are seeking.

Based on everything I've read on here and heard elsewhere is that the response rate for postcards is anywhere from .5% to 2% and letters are around 5%. 

After I determine what properties interest me I look up the owner on the assessor's website then contact them directly via phone call and if I can't locate the number I will send the owner a postcard/letter. 

Take your few thousand and send out postcards, door knock, call for sale by owners, or houses with a for rent sign out front.

Have you used the yellow postcards or letters for your marketing?

It is a lot easier to sit in your house and click a button to send 2,000 postcards than to pick up the phone and call someone, much less drive to their house.