There are 3 ingredients to a successful direct mail campaign:1) A highly targeted motivated seller mailing list (absentee, probate, pre-foreclosures are some examples);2) A well crafted letter that appeals to your motivated seller and makes that seller call you; and3) A follow up system (send several letters and when they call and if they've shown some motivation, follow them up until they sell their house to you or someone else)The above is what happened and what I've learned in my real estate business.

One of the simplest metrics you might look up is rent to price ratio.

@David Jay...yes in it's simplest form that would be the process, but believe me I have heard all kinds of requests for pricing from budget cost to cost per sq ft. and without specificly defining what they want or need done(many times they don't know). 

Decent from a cash flow perspective and has all the ingredients for appreciation.

The first and probably the simplest is short sales.

first and simplest action is to call around to local small banks and ask if they will refinance the home for you. i've heard of people calling dozens of banks until they got one to say yes. try this podcast out https://www.youtube.com/watch?

This is likely by far the simplest and easiest way.

To me, good ethnic food is when it's not too fushiony, but just well done and with good ingredients.

But those are two key ingredients that you can be working on now. 

The simplest way to analyze STRs is by comparing revenue to the acquisition price.