If you look at companies carrying a lot of cash on their balance sheet, there are people in the finance department that have that as their only job.

Google “skip trace service” in the city where the property is located; they will find the departed tenant for a small fee.

Cir. 2001),[1] is a U.S. antitrust law case, settled by the Department of Justice (DOJ), in which the technology company Microsoft was accused of holding a monopoly and engaging in anti-competitive practices contrary to sections 1 and 2 of the Sherman Antitrust Act.This is what Amazon wants to avoid. 

If the mailing address for the owner is the same as these clearly vacant houses, another trick would be to call the water department and ask where they are sending the water bills for these houses.

Properties posted for foreclosure will be listed on the county clerk's website. https://www.dallascounty.org/department/countycler...

Give this video a watch from the Ohio Department of Commerce Division of Real Estate.

@Christopher Phillips I completely agree, if the only reason you are getting your license is for MLS access, it will cost you dearly.

You can find out whats allowed on an industrial zoning by visiting your local planning/building department either online or in person.

Right now you are in the getting taken advantage department.  

I have a kid who's interested in real estate and he got a job working in the closing department at a large lender.