It's not impossible, but there's a very small percentage (I'm thinking single digit percentages) of sellers that list on the MLS who are willing or able to do a LO. 

I'm currently writing my yellow letters and one of my leads is a trust.

Some can't balance the budget anyways.GA is mostly a NON-JUDICIAL state meaning there is a power of sale clause in the mortgage docs allowing the lender to give a default notice and demand letter followed by notice in the local legal organ (newspaper) for 4 weeks with the foreclosure date set.Judicial in GA is hardly ever used except for title clearing and other oddball issues not usually seen. 

1) send them some yellow letters or if your ok with cold calling like I am then look them up on spokeo and get their number.

The law says that no unlicensed entity can receive 'any' considerations due to the purchase/sale of real estate.That means gift cards, credit points, discounts, cash, etc at closing.Like @Dev Horn says if you pay a flat fee for each lead then that isn't a consideration for closing any transactions and it would be strictly lead generation.If somebody brought me a deal and I closed on it before paying them If I was fearful of paying them for it bc they were unlicensed then I think I would simply give them the option to have money out into a marketing campaign for them to manage.Like buying 1000 direct mail letters with their information on it bc that would be you putting money into marketing vs giving a consideration.

So far I've sent all my out of state owners letters (300) and received about 10 calls.

I do my multiple option offer strategy in the form of a letter of intent.  

I ask this because I recently started my first letter campaign (FINALLY!!)

Thanks Jon , I figured when I make offers if the seller got a letter from a company , they would take it more serious

Some of you might hate yellow letters or post cards, though they work, they stand out from the crowd.