One can do better by buying treasuries and zero risk and then margin that bond and easily use those funds to buy more and more bonds to compound their return with basically zero risk.

It may only be $20 month but that's still a loss and compounded will eventually add up. 

That compounding % you can save over the course of a loan is free $$$$$.  

Do the interest rates they get from mortgage payments work differently than interest rates from the stock market (i.e. are they compounded more often or something?)

Comes in tubes and is an elastic type compound to fill cracks .

It seems like all the vacant lots have turned into small compounds with multi units.

I can be a success in old age like kfc’s founder however if done in my 20’s it all compounds.

I plan to reinvest my profits to compound my earnings and expand my portfolio to multiple properties within three years, or earlier if the opportunity presents itself. 

i would keep building up my 1-4 unit buildings as much as i could , sooner or later you will be maxed and unable have those great terms . i often have people say  they wish they could do what i do . of course they could  , but starting to invest in real estate is so much better the younger and earlier you start . think of it in the same way as compounding interest ,plus you  hopefully get appreciation as well :)   don't forget who is actually " buying " these buildings and providing you with the passive income . there will always be time to be tied down to a large mortgage and your dream home :) once you are comfortable your tenants will be buying you your dream home . 

Well @Ron Alexander, now you are compounding your rabbit hole.