Which means you are relying on mostly luck.

But don't rely on e-mail.  

I would suggest relying on a quality PM's input as well before you spend too much time looking at various options.

The drought is a massacre on the smaller populated towns that primarily rely on ground water..  

Don't rely on any single vendor for your business.  

Well, he says that he used to be an active investor but he got tired of doing that so now his business relies on his students success.

There is a "City Directory" for all good size cities with cross reference telephone numbers to the address, now, I've not used these in several years, I know many don't have landlines at home and rely on a cell phone, if you can't call, send a note.So, this IMO, but I wouldn't mention short sales unless I knew they were in distress.BTW, make sure you never use the "F" word in a letter soliciting a seller, the "F" word is FORECLOSURE! 

Don't rely on or spend a lot of time on the system that you are using for your business because its not the system that makes the business its you that makes the business.

@Robert Shearer  be wary of relying too heavily on credit cards as that can get you into a mess of trouble.

@Christian Kenworthy  Zillow is ok, for basic information, but I wouldn't rely on it to be very accurate.