I work in real estate and look forward to emailing all of my colleagues across the state about warning any clients of using this service when moving into a new home...
Only offer homes in cabled areas and you should be fine. The rest will just have to tough it out with capped services like HughesNet, Verizon, AT&T, etc. BTW, Comcast has implemented a data cap, and you can bet other cable service providers are sure to follow.
Also, make sure all your clients take the time to fully investigate any purchase before buying, find a local retailer to explain it, and carefully read the contract to understand whether or not the product will meet their needs.