This is really clever! If you have a wifi network at home or at your business, why not make some extra cash with it? Especially if you are in a place with no hotspots available you could get a quite decent client base. A company called Tomizone lets you share revenue with them 50/50, they provide you with software for your router and you’re good to go.
I’ve only seen them operate in New Zealand and Fiji but it says on their website you should be able to do it in other countries just as well.