(which is me) diversity my friends diversity. 

It needs to have a diverse economy and have a growing population.  

There were some great graphs in one of the Dallas Chamber of Commerce digital publications showing how diverse the economy is here (available for free online).Having said that, it'll be interesting to follow the long term economic impact of the inaugural LNG (liquefied natural gas) exports of the US starting this February/March at the Sabine Pass port by the TX/LA border and other upcoming ports. 

There are small multi-plexes that you can find in Sacramento and elsewhere in the Central Valley that can give you a bit more diversity in your income stream at similar prices to a home or condo in Sacramento. 

Rule #1 In my book, you make your money going in, and east orlando is extremely diverse in the quality of neighborhoods.

From what I learned so far REI seems to be a very diverse business.

City must have diverse employment not reliant on one single industry and with a wide range of Pink, white and blue collar jobs3.

Welcome @Neil Hauger , your portfolio is pretty diverse is that by accident or on purpose.

Just to piggyback on Ned Carey and Marco Santarelli's points about jobs - you may want to consider who the major employers in your chosen area are (and the diversity of those employers)...

I'd like to know about as many successful RE investors as I can so I can have a more diverse perspective.Joel Owens I know there are plenty of books, but the books aren't want I'm looking for, it's the investors themselves.