Know why you don't read about those, because it doesn't sell books, it can't readily be monetized by some "Guru", it isn't sexy and flashy talking about how to get rich SLOW, no, everyone wants to read that all they need to do is change a mindset and congrat's a check is in the mail for tens of thousands. 

Since you're 16, try learning a few different things to see what you enjoy and can monetize.

I didn't move forward with it because I couldn't find a good way to monetize and scale the business.

Good tenants are good pet owners, period.By accepting pets, I can rent places faster, they stay longer, and they pay more.Instead of automatically denying them out of fear, figure out how to screen properly, establish solid rules, policies, and procedures, and reduce your risk while monetizing this niche.

To them- going from renting an apartment paying $11-1200 /mo, to owning a 3 unit with -$500 / mo net cash flow- its actually a positive 700+ difference.

This takes a little time but most people skip right over this step trying to monetize their offering before their ready...

We should all be purchasing below market value and creating value maximizing optimizing and  monetizing spaces.  

They can also help you monetize pets.

That is called "monetizing debt" and the only consequence is increased inflation.

Using software to optimize your vetting process isn't the entire due diligence process, it's only part of it.You mean analysis software like the kind you sell (or monetizes through ad revenue)?