Not everyone who purchases a duplex is an investor who concentrates on making money, much less cash flow..

Forget abut real estate, concentrate on women.

You should concentrate in your area,  Brandon Turner says.............................Yes, I am too cheap.No ( ---- puts on his bragging suit ---- ) my daughter knows very little about RE, she's a PhD graduate in some nerosciency stuff that's way over my head.

HOA becomes insolventHOA doesn't put away enough money in reservesIf one entity buys more than 20% of the unitsIf the investor concentration exceeds 50% and there are other reasons but those are the ones we see most oftenIf it's non-warrantable, you've essentially bought into something, through no fault of your own, that you will have a difficult time reselling because it will be difficult to get financed. 

So I concentrate on other areas until metro Atlanta corrects itself. 

Most HELOCS have close to the same rates, so concentrate on those with the highest CLTV and the additional features you might want? 

Concentrate on those applicants that are most deserving.

I would concentrate on finding a way to pull the equity out of your property without selling.Keep a very close eye on future appreciation/equity growth.

Clearly the requirements are mutually exclusive.I've been trying to concentrate on 2-4 plexes that aren't too horribly far away.

Michael Blank likes to concentrate on the investors' first deal in his podcast (granted it's not always syndication, but still very helpful.)