Facebook WiFi allows your customers to leverage their Facebook credentials to check into your business or interact with your Facebook page to get access to free WiFi on your premises. It’s secure and easy to setup.

Facebook Wi-Fi for Powerful Marketing | Netgear

So how does this help you the small business owner?

Every time someone checks into your business Wi-Fi on Facebook. Its instantly shared with all of that customers friends on Facebook. So, Thant means for every one customer that checks into your business, there is the potential of hundreds of new people to be made aware of your business! Your customers become your marketers. Awesome!