That's a little better than some high-yield savings instruments, but not by much and with significant risk exposure.

Better use an automated dialer for those cold calls because you'll have serious hand damage by the time you get some positive responses with the script you are using.That being said, I salute you! 

Put all the tools in place that you'll need (a good email marketing platform that allows you to automate, a solid and sleek lead generation flow, a concerted SEO strategy, etc). 

An algorithm is just automated instruction- basically a detailed formula or set of formulas that are linked to eachother.

By security, do you mean security instruments?

Once you develop a system and automate it as much as possible it will help you be more efficient and minimize time between tenants. 

I focus on construction technology, CRM (Microsoft Dynamics 365), project efficiencies, and business operations (Microsoft Power Platform, Power BI, Power Automate, Power Apps). 

In a blow to our operation, our handyman, who had been instrumental in renovating units and handling tenant work orders, who had a lifetime of experience in the type of work we needed, was diagnosed with cancer in the spring and passed away a few months later.  

There were two good presentations on apps and technology and how to use them to automate your business. 

With a land contract I'm not sure why you would need a mortgage too since both are security instruments.