I put the cash from the refi back into more mutlifamily units that produce more rental income. 

I'll do that when I meet my investments are producing my final goal of $X.

If you purchase a rent ready RE investment this could be 0%, but at the opposite extreme a good brrrr can produce the now elusive infinite return (I have achieved this on most of my RE investments but believe it is very challenging in the current market to bp not be cash negative after the refi to extract the added value.I expect to make an offer this week.  

This amounts to lost opportunity because if you had purchased RE, at the closing it can start producing return. 5) ADUs detract from the existing structure whether this is privacy, a garage, or just yard space. 6) this is related to number 1, but there are many more buyers looking to purchase homes for their family than there are RE investors looking to purchase small unit count properties.

It would still be based on the revenue it produces.

BP Real Estate Podcast producer here.

Then I wrote 3 books, became the person in charge of education in my REI and had to produce presentations every month (at least 2) for it, and before I knew it,...It's not as hard as you think, at least it was for me. 

Some of our deals produce out size returns, but most are in the mid teens.  

You need to look at return on equity, how much cash flow can be generated putting your equity to work vs the cash flow this property will produce.

So they engaged me to produce results..