At the end of the day if it produces a return that you're happy with, right? 

But, not everyone can afford to dabble in multi-million dollar properties.Unless you purchase single-properties at great discounted prices, multi-unit properties, even duplexes always (most-likely) produce profits 500% more than single family homes because multi-unit usually cost 30% to 40% less per unit.

Why recommend a book or training, etc if it never produced and results other than motivational information?

I just started to practice analyzing deals ( used up the free 5 trials for rental calculator, so basically made an excel using old youtube videos on the 4 block technique figuring out CoCROI. )  What i've realized for my area ( Houston, TX) is basically anything over 130k basically produces 0 or negative CoCROI because ultimately your rent is the total income you get and subtract expenses(which usually adds up to around 700-800 bucks be conservative) and your mortgage(which would be around 500-600 bucks a month for a 100k-130k loan)most of the homes near Houston average (base on craigslist, rentometer, realtor.com) 1300-1600 on rent for a traditional 3/2 SFH.

Regardless of how many systems you have to produce leads and how hard you work those leads, you simply can't get to them all.

Although Amazon’s starting salary is $15 per hour with benefits, the company is realizing there is not a lot of upward mobility, said Jennifer Mellor, chief innovation officer at the Greater Phoenix Chamber of Commerce.

Its an old houses that i am currently renting and produces me $200 in cash flow.

If it's your primary residence, it produces zero cash flow and you don't get  BAH as a reimbursement for housing expenses.

The more active, the higher the return, the more passive, the less the return.If you have a high income producing job, your best bet may be to continue with your job and work on spending less and saving as much as you can and then investing with what others have mentioned in syndications or become a lender.

I've read that when it comes to rental properties, the Class C/D areas tend to produce higher ROI overall but obviously they are in a less desirable area.