This kind of thing is so penny smart, pound foolish. If I ever see that sign, it's immediately going on my Instagram, telling everyone I know to never stay at such a place.
I'm still never staying at AirBnB's when it actually matters because they completely screwed over my gf when she booked a bachelorette party and the owner literally sold the property without cancelling the reservation and the new owner rebooked the same site, also using AirBnB. AirBnB just offered a refund, even though the monetary damages were easily 10x the cost of the reservation and obviously permanent in the fact that in ruined a major life event.
Say what you want about the amount of money your company will make. Reputations take a lifetime to build, and most people have a grim trigger when it comes to being screwed over.
Airbnb and Hertz are two companies in an ever-lasting battle to prove who hates their customer more.
It's VERY easy to create homes for these guys - if you've ever seen someone with a large log that has lots of little holes drilled in it, they were likely prepping a Mason Bee habitat. Ideally, they burrow into hollow, dry grass stems that broke off at some point in the fall.
I try to tell people about this bee because it's so easy to make homes for them. Just make sure to move the home every year, or it becomes too easy for predators to find them.
edit: also worth mentioning this bee is so docile, it usually only stings when it's squeezed or wet, and its sting is very light, and the hook is unbarbed. Better than honey bees in so many ways.
You can start out simple, but you might need to be more involved if you want to prevent the spread of parasites since they are more easily spread when all the mason bee larvae are in one place.