Improve your brick & mortar SEO. Ensure store information is clearly available and accurate everywhere (website, Facebook, Google Maps, etc). Provide simple directions on your website (sometimes GPS directions leave a lot to be desired). Minimal Search Engine Optimization: link website to social media pages and blog posts; put contact details on every page; provide unique content updated regularly.
You are offering Free WiFi to your customers, or to draw customers in, but what is the real Return On Investment? leverage SMART WiFi to drive revenue: Advertise on the portal; market to on-site customers; post-visit marketing.