But, then I see a nearly identical unit in the complex for rent for $650.

Or maybe a tenant prefers a dark middle unit so that's the one that's higher.In another case, I have one building with almost identical units and the same lease start date, but the rents are different because one tenant has a Section 8 voucher, which came in slightly lower than the asking rent.

Send tenant 2 identical letters demanding payment - 1 certified, 1 regular mail with 'Address Correction Requested.'.

When you get credit/background reports back, you have to verify your identity with Experian. 

A personal identity is stolen every 2 seconds.It is good you asked first.Do you have an accepted offer and need the funding to close?

We made the mistake of showing tenants who liked another one of our properties but weren't looking to move for 2 months an identical house that we purchased and were doing a complete rehab of it.  

If I had two identical offers, but one was FHA and one was USDA, I'd take the FHA every time, and conventional above either.

So if two offers that are identical come in and one has a copy of the check and one does not, which team is more on the ball and ready to roll?

They will likely not be able to disclose very much information about their identity anyway.  

I heard a near identical question today on the Dave Ramsey show, and I actually agreed with the advice he gave.