I know that there isn't a one size fits all model, but efficiency to me is always the most important; measured by how much money does my $1 dollar generate - i.e. % ROI.

On the other hand, you could use the same credit card to go out and buy new blue jeans because you want some, same 15% interest rate - bad idea unless you are a blue jeans model and that purchase is going to make you money greater than the 15% interest cost.regarding the note above - if you are using credit to increase your credit score, check with your own trusted adviser first.  

Jorge, I highly recommend you look into eXp Realty, which is the fastest growing brokerage in the nation due to our revolutionary, disruptive business model.    

That's what my business model is based on.

I would research until you have found what your skills, expertise, and network bodes well with, and dive in full force.

Some of these other business models are very intensive to run for yield and unless scaled up to very large sizes do not make sense to own unless the investor wants to be an owner operator which can be self limiting.  

A model match comp sold for $120k with a 2k concession.  

It's sort of the Hedge Fund model (except those rarely get 20% of the profits...it's ALL in the backend except for an annual management fee.) 

Also, a good role model for my two teenager daughters.  

Leveraging other peoples time and expertise through outsourcing can be very powerful as long as you have the right teams.