You can then send them a letter, postcard or call to find out if they are interested in selling.

I'm planning on using Post Card Mania - I believe they provide lists...have you heard of them?

I would like to know if I should disclose that I am a realtor when mailing yellow post cards and letters to property owners. 

Mailed postcards ...nada (but only did 1K) I know I should do more.

I think if you have "boots on the ground" in place in NY and/or don't mind making the trip then you should take advantage of your knowledge of the local market.I am not sure where you are getting your list of apartment owners from, but I typically use a cheap postcard on my first mailer to "scrub the list". 

You can set up for certain actions to prompt an automatic postcard to the address in addition to the email or call.   

One of the strategies i have seen in the past was sending post cards or some sort of material to agents that recently got licensed.

For example, I sent out some post cards to cash buyers in my market and one of them called back and asked how did I got his information.

I wanted to try a different approach as I'm sure absentee owners are getting flooded with postcards and yellow letters from different investors.What are your thoughts on these lists working in the Memphis market?

You door knock, you call people, you talk to people at the grocery store, send postcards, etc.