On the lease, he'll pay me $100/m over my HELOC payment and all other expenses, including the refi cost, inspections, title work, etc... 

And it can work really well for you as long as you pay attention to the statute requirements.In order to defer all tax you are selling investment real estate and buying investment real estate of at least the same value you sold. 

You're going to end up paying a lot more interest on a heloc than a 2nd mortgage, if you intend on holding that debt for more than a couple years. 

I own a billboard easement in Hardin County Texas. 14k VPD that pays $3k per year.

House hacking is a great start since you're paying rent already.  

What I've realized is that a lot of these companies that do pay for housing stay in the larger apartment complexes because the companies pay for it.

I guess really you’re not paying it, the owners are.

Quote from @Sami Gren: I start by making the original tenant fill out a form requesting to add a new renter, and they pay me a $50 processing fee (I charge a $50 fee any time I make changes to an existing lease). 

Everyone associated with living there and/or paying for the unit goes on the lease.

I only pay for BP leads and all other business comes from my sphere/referrals.