Robbie - first thing that comes to mind is renting out the rooms individually on shorter term leases (co-living model). 

We had the amazing opportunity to be able to talk about our journey and business model on podcast 103. 

This has allowed us to provide all of those little things that can improve the guest experience, without debating budget for things like zip lock bags, tin foil, etc.We also evaluate all our potential new owners to determine if it's truly a good fit for us and our model. 

It was an up front payment to receive the modeled layout of the home, and they had an individual go to the house to do the mock ups.

I provide scanned copies of all invoices, but that's my business model.

The financial model does not work long-term. 

Their FAQ says that you can move to a subscription model if you want your listing to be higher in the ranks and it sounds like they offer some more services.For free, it might be worth a try.

There's not a lot of money in this model, it's more of a ministry. 

Also, there are more things to consider than max ROI.Most people start by picking a particular type/style of property that they like for some reason (usually a gut decision).

Its also classic and never goes out of style.