My parents dabbled in it for as long as i can remember but used it as a means of diversification instead of a primary investment strategy. 

Does the bank like these loans more than the 'one loan secured by one property' conventional loan because it spreads out their risk (through a kind of property diversification?)

If you had to use your own money and your personal leverage (assuming you're not ultra-wealthy), you'd likely spend your whole life buying units before you were anywhere near diversified.Unlike the stock market, where you can be fully diversified with $1000 and a couple hours of open accounts and buying mutual funds.So, in my opinion at least, focusing on diversification should not be your goal...for that -- and other -- reasons.

Great service for banking and insurance, but their financial advice is likely to be fairly conventional: mutual funds, diversification, etc.  

Diversification is Key I have always believed, even more so during times of heightened volatility, that diversity is the key to any successful business or investor strategy.

My criteria now that I have been investing for a while now is that im looking for growth in jobs, population, job diversification, landlord friendly, business friendly, rising market and familiarity in that location.

Foreclosure auctions in major metropolitan areas are attended by a number of “professionals” who have been doing this for a long time; they are knowledgeable, experienced, and have enough capital to buy numerous properties so that they engage the power of diversification.  

In addition to asset classes, geographies, and operators, your diversification strategy with your passive investments should also include business plans.

Larger pools of money offer lower rates because their diversification and size offers them enough protection that they can do that.  

. - Geographical diversification is important to me - I want to avoid having all-eggs-in-one-market-basket, would appreciate advice on how big I should go in each market to balance this goal against the overhead of having too small a portfolio in each market.- We’re planning to move our primary residence over the next couple years as well — are there any concerns with getting a decent rate mortgage for our personal home if we get a bunch of rental property mortgages in the meantime?