I can't tell you how many Brick and mortars I go to that don't offer wifi but it's a lot. In my opinion, they're missing a huge opportunity to learn about customer behavior and market to these customers.
I was meeting with a peer today over coffee and we were discussing ways to break into this space as a service and the best we could come up with goes like this.
WiFi as a Service + Email Marketing
So the wifi piece is simple, we own the hw and the contract with the ISP for wifi and serve up the service to customers. We track behavior for customers on the network, segment and market to these users.
Email marketing will tie into the wifi piece as its always adding to the subscriber list, but you need to be capturing email addresses and time of checkout so you can track behavior segment and market to users.
The joint service would provide customers with a dashboard that tracks users, behaviors, value per customers, campaigns etc.
I'm not sure how to charge for this but demonstrating value would be very easy.
Once you get recurring rev flow, you would Upsell cross sell services like ad services, content strat and creation, app/web dev, etc.
Just an idea...