So you want to let your customers connect to the Internet in return for a Facebook like? Facebook WiFi can help. It lets your customers check-in at your location and spread the word about your business in the process. After checking in, people are asked if they want to like your page.
The more check-ins your page gets, the more its ranking increases in search. This video gives you a better idea how you can turn your router into a WiFi hotspot to target Facebook users.